KR100566714B1 - Biodegradable molded article and manufacturing method thereof - Google Patents

Abstract

Biodegradable molded articles; a process for producing the same: and compositions for foam molding packed in a packaging film bag to be used in the production. A bowl-type container( 10 a), which is one of the biodegradable molded articles as described above, consists of a bowl body( 11 a) comprising starch as the main component and a coating film( 12 ) having at least hydrophobic properties and comprising a biodegradable plastic as the main component which is bonded to the surface of the bowl body( 11 a). This bowl body( 11 a) is formed by steam-foaming molding a material to be molded which is in the form of a slurry or a dough containing starch and water. The coating film( 12 ) is closely bonded to the surface of the bowl body( 11 a) either directly or via an adhesive layer. Compositions for foam molding packed in such packaging film bags can be easily stored and molded.

Description

Biodegradable moldings and methods for manufacturing the same {BIODEGRADABLE MOLDED ARTICLE AND MANUFACTURING METHOD THEREOF}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a biodegradable foamed molded article containing starch and a method for producing the same, or a composition for foam molding which is suitably used for the production of the foamed molded article, and in particular, a container for food, a molding buffer, and a gas (GES). The present invention relates to a biodegradable molded article that can be suitably used as various disposable foamed molded articles to be discarded after use in a packaging dish or the like, and a method for producing the same, and a molded article for foam molding which is suitably used for the production of the biodegradable molded article.

Generally, as a disposable molding to be discarded after use, a plastic molding and a paper / pulp molding are the mainstream. This is also required depending on the use of the molded article, but generally, the material of the disposable molded article requires some degree of durability and strength, and at the same time, ease of molding is required.

However, in any of the above-mentioned plastic moldings and paper pulp moldings, use as a disposable molding includes various problems described below.

First of all, plastic moldings have a problem of incurring unusually high heat during incineration to damage incinerators or additionally generate environmental pollutants such as dioxins. In addition, the landfilling of the plastic molding also does not decompose the plastic at all in the natural environment, so it is impossible to bury the plastic again at the place where it is once buried. In addition, the amount of waste has increased in recent years, and securing of a landfill site has become difficult every year. In addition, plastic moldings do not readily decompose, contaminating the natural environment over time.

In addition, since the accumulation amount of fossil fuel, such as petroleum, which is a raw material for plastics, also decreases every year, there is a fear that the plastic molded article will become more expensive than before.

On the other hand, in the paper and pulp molded products, since the incineration treatment is easy to decompose even in a natural environment, it is superior to the plastic molded products in this respect. However, because trees, which are the raw materials of paper and pulp, have a long growth cycle, the consumption of a large amount of paper and pulp greatly reduces forest resources. Reduction of forest resources not only greatly destroys the environment of the region, but also from a large point of view, the absorption of carbon dioxide by the forest is greatly reduced, accelerating global warming due to the increase of carbon dioxide in the atmosphere. .

Therefore, in order to cope with the above problems, in particular, in terms of the environment, recently, as a method for processing molded products, the disposal process is gradually shifted from disposal to recycling.

However, in the recycling process, for example, a food container, which is one of the important uses of the disposable moldings, is not removed from the residues such as food waste and seasonings attached to the container before the container is recovered by recycling. Can not be done. This is because the incorporation of impurities as recycling raw materials should be avoided as much as possible.

Since the removal of these residues is usually by water washing, the result is an increase in the amount of wastewater discharged, which leads to other environmental problems that cause water pollution such as rivers and oceans. In addition to the fact that the removal of the residue itself takes a great deal of time and effort to reduce the efficiency of recycling, in the present situation, there is a problem in terms of cost because the recycling system is not sufficiently established socially.

Therefore, as a new disposal method of moldings with different recycling disposal, a technology for disposing of molded products by biodegradation using microorganisms has been developed and attracting attention. In this disposal technique, since the molded product is molded from natural polymers such as various biodegradable plastics and starch as the main raw material, it is possible to avoid the above-mentioned various problems.

In particular, in the biodegradation disposal technique, a technique using a natural polymer such as starch or protein has been attracting attention from the practical point of view. This is because the various biodegradable plastics have the same excellent quality and performance as the conventional various plastics (non-biodegradable or hardly degradable), but have a problem that the biodegradation rate is actually slow.

For example, when the thickness of a molded article formed from biodegradable plastic is increased, it takes a very long time to completely decompose, and it is impossible to increase the volume of the molded article in practical range. In addition, when a molded article made of the biodegradable plastic is used, in particular, in a disposable container or the like, mixing with the food residue integrally becomes a treatment method that does not burden the environment most. However, since the decomposition rate of the biodegradable plastic is much slower than that of food residues, it is difficult to carry out mixing treatment. In addition, in general, when the molded article has a thickness or strength, it is difficult to grind, so that it is difficult to grind to improve the decomposition rate of the biodegradable plastic. Therefore, it is virtually impossible to mix-process the molded article made of the biodegradable plastic.

On the other hand, starch, protein and the like have good biodegradability, are easily decomposed even when the volume is increased, and plant starch and the like, which are mass-produced in agriculture, can be used. Since most of them are used as a polymer, there is an advantage in that it is possible to obtain a molded article having a suitable thickness and heat insulating property.

As a technique for disposing by biodegradation using the starch or protein, for example, (1) Japanese Unexamined Patent Publication (Kokai) No. 5-320401 (published date: December 3, 2015), ② Japanese Unexamined Patent Publication Published Japanese Patent Application Laid-Open No. 7-224173 (published date: August 22, 7, 2015), ③ Japanese Patent Application Laid-open Publication No. 7-10148 (published date: January 13, 7) ④ Japanese Unexamined Patent Publication No. 2000-142783 (published date: May 23, 2012), ⑤ Japanese Unexamined Patent Publication No. 7-97545 (published date: April 7, 2015 11) and the like have been disclosed.

First, in the technology of ① and ②, since starch natural material is used as the main raw material, it has the advantage of being able to exhibit good degradability as compared with biodegradable plastics and excellent in the variety of molding shapes even when compared to paper and pulp. · It causes problems such as poor moisture resistance, limited use, and moisture proof storage.

Next, in the technique of ③ and ④, the molding is molded using starch or its various polysaccharides as a main raw material, and a natural resin (dammer resin, shellac resin, etc.) is formed on the surface of the molding to improve water resistance. ) Is coated to form a water resistant coating.

However, in molded products (including foamed moldings) obtained by molding starch as a main raw material, fine bending occurs so that the surface cannot be completely flat. Therefore, as a simple coating method, a fine coating is applied at a position corresponding to the uneven portion of the waterproofing film. Needle holes are likely to occur. Therefore, even if a certain water repellency effect can be expected, it is difficult to give complete water resistance. In particular, when moisture resistance is required, it causes problems such as moisture is easily absorbed from the needle hole of the water resistant film or the molded product is easily deformed.

Furthermore, in order to apply | coat, the said dimer resin, shellac resin, etc. must be melt | dissolved in organic solvents, such as alcohol. For that purpose, when the organic solvent is removed after the coating treatment, problems such as manufacturing facilities are caused, such as the necessity of a large-scale apparatus to prevent the diffusion of these organic solvents in the air and contaminating the air or the surrounding environment.

Next, in the technique of ⑤, the biodegradable coating agent in which aliphatic polyester is dissolved in the halogenated hydrocarbon is applied to the surface of the poorly biodegradable material made of starch or the like as described in the above ③ or ④. have. In this technique, in order to use the dip method (immersion coating method) which is a specific coating method, it is possible to form suitable water-resistant coating also for the molded object of a complicated shape.

However, in this technique, it is necessary to remove the halogenated hydrocarbon used for dissolving the coating agent, which causes problems such as the need for a device for preventing the diffusion of the halogenated hydrocarbon, as in the technique of (3) or (4) above. In addition, since halogenated hydrocarbons are not good for the human body or the environment, and the halogenated hydrocarbons specifically mentioned in the technique of (5) are those in the Huron system (CFC), they should not be scattered in the atmosphere as much as possible. As a result, a problem arises in that a large airtight chamber or a recovery apparatus is required as the apparatus.

In addition to the above-described techniques, there is a method in which waxes or hydrophobic proteins are prepared with a coating liquid and then applied to the surface of the molded product. However, in general, it is difficult to apply the water-resistant surface film sufficiently uniformly and completely to the entire surface of the molded product. In the case of flat moldings such as flat plates, the application is relatively easy. However, in the moldings containing starch as the main ingredient, irregularities are easily formed on the surface thereof, which prevents uniform film formation, and the cross section of cup or ball shape is almost circular. If it is a molded object, it is necessary to rotate a molded object and an application apparatus, and the difficulty of application | coating further increases.

Moreover, even if the coating liquid can be sufficiently uniformly applied using, for example, a dip method, the coating liquid on the coating hardens and flows down to form into a coating, which also causes a problem of unevenness of the coating.

In addition, since the wax has a relatively low melting point, there is a problem in that the wax is weak in heat resistance. In addition, the hydrophobic protein does not need to use an organic solvent having a relatively good heat resistance, and since a catalyst based on water is often used, there is also a problem in that the molded product absorbs moisture and causes emulsification and deformation during application.

There has also been conventionally proposed a technique for laminating a waterproof film without applying the waterproof film on the surface of the molded article. Specifically, for example, ⑥ Japanese Unexamined Patent Publication No. 11-171238 (published date: June 29, 2011), ⑦ Japanese Unexamined Patent Publication No. 5-278738 (Publication date: October 26, 2015), (8) Japanese Unexamined Patent Publication No. Hei 5-294332 (Publication date: November 9, 2015).

In the above technique (6), the container obtained by the pulp molding method is covered with a non-water-permeable or non-absorbing protective layer without forming starch. In this technique, there is an advantage that the plastic coating technique can be almost applied as a conventional paper container, but the pulp molding main body is made of fibers, so that the biodegradation rate is slow, and it is impossible to dispose of it in combination with food residues, As long as it is difficult to apply a thickness to the container, there is a problem that it is not suitable to extend and form deeply, and is not suitable for producing a variety of moldings.

On the other hand, in the technique of (7) and (8), a biodegradable container is manufactured by coating a thin film of biodegradable plastic on the surface of a biodegradable container made of natural polysaccharides, proteins, or chemically modified in the biodegradable range thereof.

In this technique, the biodegradable plastic is used as a thin water-resistant thin film, while the container body is molded into a container having a sufficient thickness of natural polysaccharides, proteins, or the like, so that sufficient biodegradability can be exhibited while exhibiting sufficient water resistance. Therefore, it is a particularly promising technique as the disposal technique by biodegradation using starch, protein, etc.

However, in the above technique (7), only the biodegradable plastic thin film of the biodegradable container body is coated, but no specific structure of the biodegradable container is mentioned.

For example, when the biodegradable container body contains polysaccharide or protein as its main component, its strength is problematic. However, the technique of ⑦ has no explanation about the strength. Moreover, neither how to specifically coat a biodegradable plastic thin film is described, for example, the formation by a coating method, the formation of a coating film in advance, and the like.

Moreover, in the technique of ⑦ above, there is no regulation on the coating state of the biodegradable plastic thin film on the biodegradable container body. The biodegradable plastic thin film may be coated in order to improve the water resistance of the main body of the biodegradable container mainly containing polysaccharides or starch, but the technique of ⑦ simply describes the coating, and how is the coating state? It is not described anywhere.

Even when using a biodegradable container for any disposable use, stability and durability as a disposable container are required, and in order for a biodegradable plastic thin film to peel easily from a biodegradable container main body, it must not be durable. Therefore, the covering state on the container body is an important requirement, but there is no consideration in this regard in the technique of ⑦ above.

Moreover, as described above, biodegradable plastics are difficult to use as thick moldings in order to slow down the biodegradation rate, but the biodegradation rate depends not only on the thickness of the moldings but also on the total amount contained in the moldings. Thus, in the above technique ⑦, it is described that the biodegradable container body is foamed and the biodegradability is improved, and the relationship between the degree of foaming and the biodegradability, and the biodegradable plastic and the biodegradable plastic of the biodegradable container body are described. Since no mention is made, the biodegradation of the entirety of one vessel cannot proceed well.

On the other hand, although the technique of said (8) is estimated to correspond to one of the manufacturing methods of the biodegradable container disclosed by said (7), in this technique, a thermoplastic plastic is melt | dissolved in a solvent and apply | coated to the surface of a biodegradable container main body, After drying it to volatilize the solvent, another coating thin film made of thermoplastic is laminated and thermocompressed. That is, in order to stably attach a coating thin film (corresponding to a biodegradable plastic thin film), it is disclosed that a thermoplastic is used as an adhesive.

As a result, as described in the above arts 3 to 5, problems such as the need for an apparatus for dissolving and using thermoplastic plastics in a solvent and preventing diffusion into the solvent are required. In addition, in the specific example according to the technique of (8), in order to use chloroform as a solvent and not to disperse it in the air as much as possible, as in the technique of (5), a large hermetic chamber or a recovery apparatus is required as the apparatus. Also brings.

Furthermore, in the manufacturing method of (8), a biodegradable container body is obtained by first forming a sheet from polysaccharides or starch, and then pressing the sheet into a mold. For this purpose, there is a problem in that moldings are not uniform in thickness, such as a deeply stretched shape such as a cup, a container tray or a packaging tray attached to a trimmer, and it is impossible to mold a complex shape such as a packing buffer. Brings about.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to realize sufficient strength even at the same time, and at least at the same time, to realize sufficient biodegradability. It is providing the molding, the manufacturing method of the said biodegradable molding, and the composition for foam molding used suitably for manufacture of the biodegradable molding.

Disclosure of the Invention

The inventors of the present invention have made careful considerations in view of the above problems and, as a result, select starch as a main raw material and prepare a raw material for forming a slurry or dough in which at least water is added to the starch, or biodegradability molded from the raw material for molding. Considering the stability after attaching the biodegradable plastic coating film to the foamed molding, in addition, the amount of biodegradable plastics such as the coating film is specified for the biodegradable foamed product containing starch as a main ingredient, or By defining the proportion of the volume of the air phase contained in the biodegradable foamed molded article, it has been conceived that it is possible to produce a very high quality biodegradable molded article, and has completed the present invention.

That is, the biodegradable molded article of the present invention includes a biodegradable foamed article molded into a predetermined shape in order to solve the above problems, and the coated film comprising a biodegradable film as a main component. In the biodegradable molded article having at least hydrophobicity, the biodegradable foamed molded article is composed of starch and its derivatives as a main component, and has a slurry or dough-like raw material for molding and biodegradable plastics obtained by mixing water therein. , By using the coating film having at least hydrophobicity, heating the molding raw material and the coating film by internal heating to heat the molding raw material itself in the molding mold, and forming a biodegradable foamed molding having a predetermined shape by steam foam molding. At the same time, the coating film is heated, softened and pressed to finally produce the biodegradable molding, including a molding-simultaneous-adhesion step of attaching the coating film to the surface of the biodegradable foam molding. It features.
In addition, the biodegradable molding of the present invention is a biodegradable film comprising a biodegradable film formed of a biodegradable foamed molded article formed into a predetermined shape and a coating film attached to the surface thereof in order to solve the above problems. In a biodegradable molded article having at least hydrophobicity, the biodegradable foamed molded article is formed by forming a starch and a derivative thereof as a main component, and heating the raw material for forming a slurry or dough obtained by mixing water therein. The molding process of steam foaming a biodegradable foamed molded article having a predetermined shape by internal heating for heating the raw material itself, and heating and softening a coating film having biodegradable plastics as a main component and at least hydrophobic, followed by compression It is characterized in that it is produced through a method for producing a biodegradable molding comprising an adhering step of adhering to the surface of the biodegradable foam molding.

According to the above constitution, starch is used as a main component to prepare a raw material for forming a slurry or a dough, which is then steam-foamed using the same, and can be easily molded even in a very complicated molding. It has a water content of and can exhibit excellent strength in view of conventional starch moldings. In addition, in order to adhere the coating film having biodegradability to the foamed molded product, for example, by using a mold such as a molding mold for molding a molded foam, it is thermocompression-bonded and attached simultaneously at the time of foam molding. It is possible to reliably coat easily to match the shape of the molding.

Since the coating film is generally composed of biodegradable plastics having properties close to plastics and has at least hydrophobicity, it is possible to impart water resistance to the foamed molding containing the starch as a main component in order to adhere the coating film. Do. In addition, it is also possible to externally impart various functions such as gas impermeability by appropriately selecting the kind of biodegradable plastics and the like.

In the biodegradable molding of the present invention, it is preferable that the occupied weight of the biodegradable foam molding in the total weight is 60% by weight or more.

According to the above constitution, the amount of biodegradable plastic having a slow biodegradation rate is suppressed to at least less than 40% by weight of the whole, so that the biodegradation balance between the biodegradable plastic and the biodegradable foam molding is good, It is possible to further improve biodegradability. Particularly, since the biodegradable foamed molded product is in a foam, the biodegradable product is good. However, the biodegradable molded article can exhibit very good biodegradable properties as a whole so that the content of the coating film is suppressed.

In the biodegradable molding of the present invention, the ratio of the volume of the air phase contained in the biodegradable foamed product to the total volume is preferably greater than 30% by weight.

According to the said structure, the surface area of a biodegradable foamed molding is large, and recovery of the microorganism which biodegrades a biodegradable foamed molding is easy. Therefore, the biodegradable foamed molding is easily biodegradable, and as a result, the biodegradability of the biodegradable molding can be further improved.

In the biodegradable molded article of the present invention, when the whole raw material for molding is 100% by weight, it is preferable to contain water in the range of 20% by weight or more and 70% by weight or less.

According to the said structure, since the water of a suitable amount of the raw material for shaping | molding contains, the foamed molded object obtained by shaping | molding has preferable water content (it is 3 weight% or more and 20 weight% or less for relief). ) As a result, it is possible to produce biodegradable moldings in batches after steam foam molding, in addition to attaching the coated film in a continuous process, or simultaneously at the time of foam molding, without adjusting to improve the water content.

In the biodegradable molding of the present invention, it is preferable that the coating film is directly adhered to the surface of the biodegradable foamed molding in a nearly intimate state.

According to the above structure, since the coating film is directly attached in a state of being in close contact with the surface of the foamed molded product, the coated film does not easily peel off from the surface of the foamed molded product. For that purpose, the coating film with respect to a foamed molding can be attached more reliably, and the biodegradability of the obtained biodegradable molding can be ensured.

In the biodegradable molding of the present invention, the coating film may be attached to the surface of the biodegradable foamed molding with an adhesive having biodegradability.

According to the said structure, using the biodegradable adhesive agent, it is possible to adhere | attach a coating film with respect to a foamed molding more reliably, and also the biodegradability of the obtained biodegradable molding can be ensured. In the biodegradable molded article of the present invention, the biodegradable foamed molded article is preferably in the range of 3% by weight or more and 20% by weight or less.

According to the above constitution, an appropriate amount of water is contained in the foamed molded article, and the foamed molded article exhibits sufficient strength. It is possible to further improve the strength and durability of the obtained biodegradable moldings.

In the biodegradable molding of the present invention, it is preferable that the coating film has a softening start temperature of 130 ° C or higher and a melting point of 170 ° C or higher.

According to the above constitution, the coating film is hardly softened or melted. This makes it possible to more reliably avoid deformation of the biodegradable moldings by heat.

In order to solve the above-mentioned problems, the method for producing a biodegradable molded product of the present invention comprises starch or a derivative thereof as a main component, and steam-molded the raw material for molding a slurry or dough obtained by mixing water therein to have a predetermined shape. Forming a biodegradable foamed molding, and adhering to the surface of the biodegradable foamed molding by pressing and emulsifying a coating film having at least hydrophobicity as a main component of the biodegradable starch, followed by pressing. It is done.

According to the above method, first, the raw material for molding a slurry or dough with a starch as a main component is foamed, and then the biodegradable coating film is heated and pressed. To this end, it is possible to obtain a moisture content of a degree sufficient to exert sufficient strength at the time of molding, and to stably attach the coating film to the main body (foaming product) having a stable moisture content. Therefore, a biodegradable molded article which is much superior to the conventional one can be produced by a simple method.

In the method for producing a biodegradable molded article of the present invention, a predetermined mold may be used in the molding step, and a method of using an attachment mold having substantially the same shape as the mold may be used in the attaching step.

According to the above method, the mold of the foamed molding and the mold of the coating film are used in the form of almost the same shape. To this end, even in the case of molding a complicated molded article, it is possible to easily produce a mold by producing a mold and copying the mold according to the mold. In addition, since the coating film using almost the same mold is attached, it is possible to reliably attach the coating film even to a foamed molded article having a complicated shape. As a result, biodegradable moldings can be produced in a simpler process.

In the method for producing a biodegradable molding of the present invention, in the attaching step, before adhesion of the coating film, between the coating film and the biodegradable foam molding, a low melting point biodegradable plastic is meltable at a temperature lower than the melting point of the coating film. You may also place an adhesive film.

According to the above method, in order to sandwich the adhesive previously formed into a film between the coating film and the foamed molded product, the adhesive is melted by softening and compressing the coated film to securely adhere the coated film to the foamed molded product surface. It is possible. As a result, a process such as applying an adhesive to the surface of the foamed molding is necessary, and it is possible to further simplify the manufacturing method of the biodegradable molding.

In the manufacturing method of the biodegradable molding of this invention, the said coating film may be previously shape | molded in the shape substantially matching the external shape of the obtained biodegradable molding.

According to the method described above, since the coating film is molded into a shape almost coincident with the outline of the biodegradable molding, even if a coating film that cannot be stretched to a large extent during molding is used, the coating film is not torn and the stretching is deep. It is possible to mold shaped biodegradable moldings well. As a result, it is possible to reliably and effectively coat the coating film on the foamed molded article.

In order to solve the above process, another method for producing a biodegradable molded article of the present invention comprises a raw material for forming a slurry or a dough obtained by mixing starch or a derivative thereof as a main component and mixing water therewith, and a biodegradable plastic as a main component. Wherein the raw material for the molding and the coating film using the coating film having at least hydrophobicity are heated in a molding mold to steam foam the biodegradable molded product of a predetermined shape, and the coating film is heated, softened and pressed. And finally a molding-simultaneous-adhering step of attaching the coating film to the surface of the biodegradable foamed molded article.

According to the above method, in the biodegradable molding obtained, the foaming molding of the molding raw material and the adhesion of the coating film are carried out simultaneously in one step. It is possible to do Therefore, it is possible to manufacture a biodegradable molded article which is much superior to the conventional one by a simpler method, and at the same time, it is possible to further stabilize the state in which the coated film is adhered in the obtained biodegradable molded article.

In another method for producing a biodegradable molding of the present invention, the raw material for molding may be sandwiched with a coating film, and then heated in a mold, and the entire surface of the biodegradable foam molding may have a biodegradable molding coated with a coating film. have.

In another method for producing a biodegradable molded article of the present invention, in the forming-simultaneous-adhering step, it is preferable to directly heat the molding raw material by dielectric heating such as high frequency dielectric heating.

According to the said method, in the initial stage at the time of foam molding, the shaping | molding raw material heats in a short time, and the whole expands uniformly. Accordingly, the pressure for pressing the coating film into the mold is strong and uniformly generated. As a result, a biodegradable molded article having high adhesion between the biodegradable foamed molded article and the coated film can be obtained.

Further, according to the above method, since the raw material for molding is directly heated without heating the raw material for molding through the mold, even if the temperature of the mold is set at a relatively low temperature of less than 150 ° C, the raw material for molding is sufficiently heated. It is possible to adhere to the coated film. Therefore, it is possible to use a coating film having a low melting point such as 150 ° C. or higher, thereby increasing the degree of freedom of selection of the coating film.

In the manufacturing method of the other biodegradable molding of this invention, the said coating film may be previously shape | molded in the shape substantially matching the external shape of the obtained biodegradable molding.

According to the above method, since the coating film is first molded into a shape that almost coincides with the outside of the biodegradable molding, even when a coating film which is not easily stretched at the time of molding is used, the coating film is not torn and has a deep drawing shape. It is possible to mold biodegradable moldings well. As a result, it is possible to reliably and effectively coat the coating film on the foamed molded article.

As a manufacturing method of the other biodegradable molding of this invention, the said coating film may be a film piece cut | disconnected in the shape substantially matching the external shape of the obtained biodegradable molding.

According to the said method, the shape of the coating film before attachment is made into the shape matching with the shape after shape | molding previously. Therefore, even when using the coating film whose main component is a biodegradable plastic with poor stretchability, a coating film does not tear and it can shape | mold the biodegradable molded object of deep elongation shape favorably. As a result, it is possible to reliably and effectively coat the coating film for the foamed molded article.

In another method for producing a biodegradable molding of the present invention, the coating film may be processed into a bag shape so as to further accommodate a molding material therein.

According to the said method, the raw material for shaping | molding is put in the thing which processed the coating film in the bag shape, and it will be in the state which substantially packed. To this end, a large number of the raw materials for molding are prepared in a bag-shaped coating film in advance, so that it is possible to preserve them for a certain period of time, and then, at the time of producing the biodegradable moldings, they are collectively put into the mold. It is ready for molding just to do it. Therefore, the manufacturing process can be further simplified.

In order to solve the above problems, the foaming composition of the present invention contains starch or a derivative thereof as a main component in a bag film processed into a substantially bag shape, and contains a slurry or dough-like raw material obtained by mixing with water. In addition, the bag is a biodegradable plastic as a main component, characterized in that it is obtained from a coating film having at least hydrophobicity.

According to the said structure, the molding raw material for foam molding is put into a bag film, and it is in a substantially bagged state. For this purpose, it becomes possible to prepare several foam molding compositions which divided the molding raw material in the bag-shaped coating film beforehand, and to preserve | save as it is for a fixed period. In addition, by steam foam molding which is put into the mold at the same time, it is possible to easily produce a biodegradable molded article having a coated film mainly composed of biodegradable plastic on its surface. To this end, it is possible to produce biodegradable moldings in an easy and simple process.

Still other objects, features, and advantages of the present invention will be apparent from the above description. Further advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

[Brief Description of Drawings]

1 (a) and 1 (b) are schematic cross-sectional views showing the shape of a ball-shaped container as an example of a biodegradable molded article showing one embodiment of the present invention.

2 (a) and 2 (b) are schematic cross-sectional views showing the shape of a dish-shaped container as another example of a biodegradable molded product showing one embodiment of the present invention.

3 (a) and 3 (b) are schematic sectional views and schematic plan views showing the shape of a cup-shaped container as still another example of the biodegradable molded product showing the embodiment of the present invention.

Fig. 4 is a graph showing the composition of the molding raw materials used in the present invention, a graph (I) based on the entire molding raw material, a graph (II) based on the total solid content, and a total amount of raw molding powder and water. The schematic relationship between the graph (III) shown by contrast is shown.

5 (a) and 5 (b) are schematic cross-sectional views showing the configuration of a molding die for molding the foamed molded product constituting the main body of the ball-shaped container shown in FIGS. 1 (a) and 1 (b).

6 (a) and 6 (b) are schematic cross-sectional views showing an example of the configuration of a molding die for molding the foamed molded product constituting the main body of the dish-shaped container shown in FIGS. 2 (a) and 2 (b).

7 (a) and 7 (b) are schematic cross-sectional views showing an example of a configuration of a molding mold for molding the foamed product forming the main body of the cup-shaped container shown in FIGS. 3 (a) and 3 (b).

8 (a) and 8 (b) are schematic cross-sectional views showing another example of forming a mold for molding a foamed product that forms the main body of the cup-shaped container shown in FIGS. 3 (a) and 3 (b).

FIG. 9 is a schematic explanatory diagram showing an example of a configuration in which electrodes are provided for internal heating in the molds shown in FIGS. 5 (a) and 5 (b).

Fig. 10 (a) is a schematic cross-sectional view showing the shape of the foamed molding molded in the mold shown in Figs. 5 (a) and 5 (b), and Fig. 10 (b) is a molding shown in Figs. 6 (a) and (b). 10 is a schematic cross-sectional view showing the shape of the foamed molded product in the mold, and FIG. 10 (c) shows the foamed molded product in the mold shown in FIGS. 7 (a), (b) or 8 (a), (b). It is a schematic sectional drawing which shows a shape.

FIG. 11 is a schematic cross-sectional view for explaining an attaching process in which a coating film is attached to the surface of the biodegradable foamed molding shown in FIG.

Figure 12 (a) is a schematic explanatory view showing the adhesion state of the coating film on the surface of the biodegradable moldings with the coating film using the post-attachment method, Figure 12 (b) is a coating film attached using the co-adhesion method It is a schematic explanatory drawing which shows the adhesion state of a coating film in the surface of a biodegradable molding.

FIG. 13 is an explanatory view for explaining the case where the production method 1 is used in the co-adhesion method for producing the biodegradable molded product shown in FIG. 2 (a).

FIG. 14 is an explanatory view for explaining the case where manufacturing method 2 is used in the co-adhesion method for producing the biodegradable molded product shown in FIG. 1 (a).

FIG. 15 is an explanatory view for explaining the case where manufacturing method 3 is used in the co-adhesion method for producing the biodegradable molded product shown in FIG. 2 (a).

FIG. 16 is an explanatory view for explaining the case where the production method 4 is used in the simultaneous deposition method for producing the biodegradable molded product shown in FIG.

Figure 17 (a) is a schematic plan view showing an example of two divisions of a state where the coating film is cut into a film piece when the biodegradable molding shown in Figure 3 (a) is produced using Production Method 5, Figure 17 (b) is a schematic plan view which shows an example of 3 division | segmentation of the state which cut | discovered the coating film as a film piece.

FIG. 18 is an explanatory diagram for explaining the case where the manufacturing method 5 (a) is used in the co-adhesion method for producing the biodegradable molded product shown in FIG. 3 (a).

FIG. 19 is an explanatory diagram for explaining the case where the production method 6 is used in the simultaneous deposition method for producing the biodegradable molded product shown in FIG.

FIG. 20 is an explanatory diagram for explaining the case where the manufacturing method 7 is used in the co-adhesion method for producing the biodegradable molded product shown in FIG. 3 (a).

Figure 21 (a) is a schematic cross-sectional view showing a state in which a seal cover is attached to the end of the biodegradable molding shown in Figure 1 (b), Figure 21 (b) is in the corner shown in Figure 21 (a) It is a schematic explanatory drawing which shows the state in which a coating film is not affixed.

Fig. 22 is an explanatory diagram for explaining the case where manufacturing method 1A is used in the simultaneous deposition method.

Fig. 23 is a schematic cross-sectional view showing the shape of a dish-shaped container as another example of the biodegradable molded product of one embodiment of the present invention obtained in accordance with the manufacturing method 1A.

Best mode for carrying out the invention

Embodiments of the present invention will be described below with reference to Figs. However, the present invention is not limited to this embodiment.

Important symbols in the drawings are as follows.

10a ball-type container (biodegradable molding)

10b dish-shaped container (biodegradable molding)

10c cup-shaped container (biodegradable molding)

11a Container Body (Biodegradable Foam)

11b Container Body (Biodegradable Foam)

11c Container Body (Biodegradable Foam)

12 covering film

12b bag film

12c molded bag film (bag film)

12g outer film (bag film)

13 adhesive layer

13a adhesive film

14 Molding raw materials

15 boundary

20a mold

20b mold

20c mold

20d mold

30 mold (attached)

40b Mold composition (foaming composition)

40c Mold composition (foaming composition)

40g mold composition (foaming composition)

The biodegradable molding according to the present invention is a biodegradable foam molding molded into a predetermined shape, and includes a coating film adhered to a surface thereof, wherein the coating film has a biodegradable plastic as a main component and has at least hydrophobicity. to be. The biodegradable foamed molding is composed of starch and its derivatives as a main component, and is formed by steam foaming the raw material for molding a slurry and a dough obtained by mixing water therein.

In the biodegradable moldings, it is preferable that the amount of biodegradable plastics, such as coating film, to the biodegradable foamed moldings is defined in a certain amount, or that the proportion of the volume of the air phase contained in the biodegradable foaming moldings is prescribed. In addition, the coating film is preferably coated on the surface of the biodegradable foamed molding in a state of being almost attached. At this time, the adhesion state is more preferably in direct contact with the coating film, but may be via the adhesive layer.

By the way, in the following description, the said biodegradable foamed molding is abbreviated as "foamed molding". In addition, the said adhesive layer refers to the state which has sufficient fluidity in the state which added water to at least starch. Therefore, the starch does not need to be dissolved in water, but may be in a state close to the suspension. On the other hand, in the said dough phase, it will be in a state near semi-solid, in fluidity lower than the said slurry phase.

Description of the biodegradable moldings shown in the present invention. Specifically, as an example of the biodegradable molding, a ball-shaped container (referred to as a 'ball-shaped container'), as shown in Fig. 1 (a), the ball-shaped container 10a is a container body 11a in the biodegradable foamed molding. And a coating film 12 which is almost in close contact with and adheres directly to the surface thereof. Alternatively, for the ball-shaped container 10a, as shown in Fig. 1 (b), the medium between the container body 11a and the coating film 1 and the coating film 12 may have a medium adhesive layer 13 on the surface of the container body 11a. By the way, as mentioned later, the surface of the container main body 11a does not need to be completely covered with the coating film 12, and may be in the state partially covered.

Similarly, as another example of the biodegradable molding according to the present invention, a dish-shaped container (plate type container) is taken as an example. As shown in Fig. 2 (a), the dish-shaped container 10b is also the container body 11b and the coating. It consists of the structure which consists of a film 12, or the structure which has an adhesive bond layer 13 between the container main body 11b and the coating film 12 as shown in FIG.2 (b).

Moreover, as another example of the biodegradable molding shown in the present invention, taking a cup-shaped container (cup-shaped container) as an example, as shown in Fig. 3 (a), the cup-shaped container 10c, the container body 11c and the coated film 12 Constitution consisting of, or as shown in Figure 3 (b) consists of a structure having an adhesive layer 13 between the container body 11c and the coating film 12. 3 (a) and 3 (b), the upper drawing is a longitudinal section of the cup-shaped container 10c, and the lower drawing is a cross-sectional view (a view of the cup-shaped container 10c from above).

The biodegradable foamed moldings forming the main body of the biodegradable moldings shown in the present invention (the container bodies 11a, 11b, and 11c) are formed by steam foaming from a molding raw material containing starch or a derivative thereof.

The starch used as the main raw material of the molding raw material is not particularly limited. For example, it is possible to suitably use starch easily obtained from agricultural products produced worldwide as main grains such as potatoes, corn, tapioca, rice, wheat, and sweet potatoes. Although the said starch should just be especially manufactured from agricultural products, you may mix what was manufactured from several agricultural products.

In addition, the derivative of the starch refers to modifying the starch within a range that does not impair biodegradability, and specific examples thereof include α-ized starch, cross-linked starch, modified starch and the like. Furthermore, it is also possible to use mixtures in which the starch which is not modified and a derivative of the starch are mixed. Therefore, broadly, in this invention, starch consists of starch (broad starch) which does not give an example, the derivative of the said starch, and mixtures thereof. In addition, unless it mentions especially "starch" in the following description, a wide range of starch shall be indicated.

As content of starch contained in the said raw material for shaping | molding, as shown in the graph of FIG. 4 "(II) of main solid content gross weight", when the total amount of main solids of the said raw material for shaping | molding is 100 weight%, 50 weight% or more 100 It is preferable to exist in the range of weight% or less. In addition, when the whole raw material for shaping | molding to which water was also added was made into 100 weight%, as shown in the graph of "the raw material for shaping | molding of (I)" of FIG. 4, it exists in the range of 20 weight% or more and 60 weight% or less. desirable. Within the range, the biodegradable molded article shown in the present invention can be regarded as a starch whose main component is starch, and can exhibit good biodegradability. In addition, the said main solid content and its total amount are mentioned later.

In the said raw material for shaping | molding, each total additive other than the said starch may be contained. Specific examples of the additives include extenders, strength modifiers, plasticizers, emulsifiers, stabilizers, mold release agents, uniformity modifiers, humectants, handling modifiers, conductivity modifiers, dielectric loss modifiers, swelling agents, and colorants.

Such additives improve the manufacturing efficiency of the biodegradable moldings, have an advantage in the manufacturing process in the manufacturing process, or improve the quality of the obtained biodegradable moldings, and reduce the cost of the biodegradable moldings, which is an advantage in the finished biodegradable moldings You can hear this. These additives are not particularly limited as long as the quality of the foamed molding and the biodegradable molding is not significantly reduced.

The said additive is an additive which shows cost reduction by increasing the said raw material for shaping | molding by adding the shaping | molding raw material, and reducing the usage-amount of starch which is a main raw material as much as possible. To this end, if it is cheaper than starch, it is not particularly limited, but preferably, if it is cheaper which also serves as waste treatment, it is possible to preferably use by-products associated with processing and manufacturing.

Specifically, for example, (1) foods made from vegetables and fruits such as celery, carrots, tomatoes, citrus fruits (oranges, lemons, graph fruits, etc.), apples, grapes, strawberries, pineapples, sugar cane, sugar beets, etc. Juice residues or salty residues or mixtures thereof produced during the production or processing of (food); (2) by-products produced at the time of manufacture of processed foods using grains such as soybeans such as soybeans as raw materials; (3) liquor sediments, shochu sediments, beer yeast sediments, wine yeast sediments, or mixtures thereof produced during the production of alcoholic beverages such as sake, shochu, beer, and wine; (4) extract sediment, tea grains, or mixtures thereof of preference products, such as tea, such as coffee, black tea, barley tea, green tea, and oolong tea; (5) oil residues left after oiling soybeans, corn, rape seeds, sesame seeds, or mixtures thereof; (6) by-products or mixtures thereof produced in refining grains such as bran, rice bran, sediment, and the like; (7) starch sediment produced by-products such as gluten wheat; (8) confectionery such as corn cups, crackers, wafers, waffles and the like, sedimentary baking residues of bakery products or mixtures thereof; (9) drying and / or powder treating each of the by-products and the like; Etc. can be mentioned. These may be used only by one type, but may mix and use two or more types.

The strength modifier is an additive for adjusting the strength of the foamed molding and the biodegradable molding (particularly, improving the strength), and is not particularly limited, but specifically, for example, various kinds of (1) to (9) as the extender. by-product; (10) sugars such as glucose (dex), dextrin, or isomerized sugar or mixtures thereof; (11) sugar-alcohols or mixtures thereof such as sorbitol, mannitol and lactitol; (12) fats and oils such as vegetable oils, animal oils, processed oils and the like, or mixtures thereof; (13) waxes such as carnauba wax, candelilla wax, beeswax, paraffin, microcrystalline wax or mixtures thereof; (14) xanthan gum, gellan gum, guar gum, locust bean gum, pectin, arabic resin, karaya gum, Thickened polysaccharides or mixtures thereof such as tara gum, carrageenan, furcellaran, urticaria (agar), arginate, and salts thereof, microorganism producing polysaccharides and plant free polysaccharides; (15) metal salts such as metal chlorides such as calcium, sodium, potassium, aluminum, magnesium, iron, sulfates, organic acid salts, carbonates, hydroxides and phosphates, or mixtures thereof; (16) insoluble minerals such as quartz powder, diatomaceous earth, talc, silicon, or mixtures thereof; (17) vegetable fibers such as cellulose, microcrystalline cellulose, paper, pulp (recycled pulp, virgin pulp), carboxymethyl cellulose, methyl cellulose, acetyl cellulose, derivatives thereof, or mixtures thereof; (18) various structures such as inorganic materials such as glass, metal, carbon, ceramic, and fibers made thereof; (19) natural materials such as shellfish, powder, eggshell, leaves, sawdust or mixtures thereof; (20) calcium carbonate, carbon, talc, titanium dioxide, silica gel, aluminum oxide, non-fiber fillers, or mixtures thereof; (21) salts such as fatty acids such as stearic acid, lactic acid and lauric acid or metal salts thereof, or fatty acid derivatives such as acid amide and ether, or mixtures thereof; (22) Glycerin, polyglycerin, propylene glycol, ethylene glycol, glycerin fatty acid esters, polyglycerol fatty acid esters, sugar esters, lecithin, sorbitan fatty acid esters, polysorbates, etc. Or mixtures thereof; (23) natural resins such as shellac, rosin, sandarac resin, gutta percha, dammer resin, or mixtures thereof; (24) biodegradable resins such as polyvinyl alcohol, polylactic acid, or mixtures thereof; (25) acetyltributyl citrate, zirconium salt solution, aluminum zirconium carbonate aqueous solution, or mixtures thereof; Etc. can be mentioned. These may use only one type or may mix and use two or more types.

The plasticizer is an additive which improves the cavity properties of the raw materials for molding and imparts flexibility to the obtained molded foam and the biodegradable molded article, and is not particularly limited, but specifically, for example, (1) to ( Various by-products of 9); Various compounds of (10) to (21), (23) and (24) mentioned in the strength modifier; (26) acetylpolybutyrate citrate or sugar-alcohols such as glycerin, polyglycerine, propylene glycol, ethylene glycol, or mixtures thereof; Etc. can be mentioned. These may use only one type or may mix and use two or more types.

The emulsifier is an additive for oil-drop-in-oil-like liquid phase by sufficiently mixing the oily additive when the oily additive of the molding raw material is added, but is not particularly limited Specifically, for example, (27) surfactants such as glycerin acid ester, polyglycerol acid ester, propylene glycol fatty acid ester, sugar ester, sorbitanic acid ester, lacithin, polysorbate, or mixtures thereof This is an example.

The stabilizer is an additive for stabilizing the produced ester state, and is not particularly limited, but specifically, for example, starch (not broadly modified) or a derivative thereof as the main source described above; (10) sugars exemplified in the strength modifier; (11) sugar-alcohol; (14) thick polysaccharides; (15) vegetable fibers or derivatives thereof, but not paper; (21) fatty acids, fatty acid salts, fatty acid derivatives; Etc. can be mentioned. These may use only one type or may mix and use two or more types.

The mold release agent is an additive which is easy to deviate from the molding frame of the foamed molded product after molding, and is added to finish the surface of the foamed molded product as roundly as possible, and is not particularly limited, but specifically, for example, 12) maintenance; (13) waxes; (14) thick polysaccharides; (21) fatty acids, fatty acid salts, fatty acid derivatives; Etc. can be mentioned. These may use only one type or may mix and use two or more types.

The uniformity adjusting agent is as thin as possible for homogeneity in the raw material for forming a slurry or dough, that is, "grains" of the raw material for molding (in this case, particles of solid content for molding a slurry or dough). It is an additive for making it a uniform and soft state, Although it is not specifically limited, Specifically, For example, starch (broadness, no formula) or its derivative (s) as a main raw material mentioned above; Various by-products of the examples (1) to (9) as extenders; Various compounds of (10) to (25) cited as strength modifiers; Etc. are examples. These may use only one type or may mix and use two or more types.

The moisturizer is intended to contain constant water in the foamed molding, and has the same function as the plasticizer. In other words, if the foamed molded article containing starch contains a constant water (moisturizing state), the fragility of the α-ized starch is reduced while the strength and flexibility are improved. To this end, it also functions as a moisturizer, plasticizer or strength modifier.

Although it does not specifically limit as said moisturizer, Specifically, For example, starch (broadness, no formula) or its derivative as a main raw material mentioned above; Various by-products of (1) to (9) mentioned in the extender; Examples of the strength modifiers are (10) sugars; (11) sugar-alcohol; (12) maintenance; (13) waxes; (14) thick polysaccharides; (15) metal salts; (17) vegetable fibers or derivatives thereof; (19) natural materials such as shells, sesame powder, egg shells, leaves and sawdust; (22) food additives; Etc. are examples. These may use only one type or may mix and use two or more types.

The said handling regulator functions as a slurry regulator, and is an additive which improves the handleability of the raw material for shaping | molding of a slurry form or a dough form, Although it does not specifically limit, All materials, compounds, etc. which were mentioned as said plasticizer, emulsifier, stabilizer, etc. are mentioned. This is an example. These may use only one type or may mix and use two or more types.

The conductivity adjusting agent is one of the factors for controlling the foaming state when internally foaming the foamed molded product as described below, particularly in the case of heat molding which is internally heated by energizing heating. Additives for the adjustment, although not particularly limited, include, for example, (12) fats and oils, for example, in the strength modifier; (13) waxes; (14) thick polysaccharides; (15) metals; (28) various water-soluble electrolytes such as salts, acids, alkali salts and alcohols; Etc. are examples. These may use only one type or may mix and use two or more types.

The dielectric loss modifier is an additive for adjusting the dielectric loss of a raw material for molding as one of the factors for controlling the heating state when forming a foamed molding, in particular, in the case of high-temperature dielectric heating and internally heat-molding. Specific examples include, but are not limited to, for example, (12) fats and oils in the strength modifier; (13) waxes; (15) metal salts; (16) insoluble minerals; (17) vegetable fibers or derivatives thereof; (28) various water soluble electrolytes referred to as permittivity modifiers; (29) Zirconium salt containing compounds, such as a zirconium salt and an ammonium zirconium carbonate solution, or a mixture thereof; Etc. are examples. These may use only one type or may mix and use two or more types.

The swelling agent (swelling agent) is an additive for adjusting the sum of the degree of foaming of the raw material for molding, to promote the swelling to form a foamed molding appropriately for the shape or use, but is not particularly limited, specifically, for example, (30) organic swelling agents such as benzylsulfonyl hydrazine compounds, azonitrile compounds, nitroso compounds, diazo acetamide compounds, azocarboxylic acid compounds, and various materials including these; (31) ammonia-based expanding agents such as espata and various materials including these; (32) inorganic swelling agents such as sodium hydrogen carbonate, ammonium alum hydrogen tartaric acid, magnesium carbonate, and various materials including these; An example is this. These may use only one type or may mix and use two or more types.

The coloring agent is an additive added for the purpose of coloring the entire foamed molding, and is not particularly limited. Specific examples thereof include (33) inorganic pigments such as carbon black; (34) natural or synthetic organic pigments which are various colored pigments such as, for example, those defined in the color index; (35) colorants of natural materials such as caramel and cacao powder; Etc. can be mentioned. These may use only one type or may mix and use two or more types.

Here, as content of the extender (it may also be expressed as an extendable additive) in the additive contained in the said raw material for shaping | molding, it is good that it is below content of the starch contained in the main component total amount of the said raw material for shaping | molding.

That is, although it does not need to contain an extendable additive (extender) in particular, it is the quantity equivalent of starch from a viewpoint of reducing raw material cost of the biodegradable molding of this invention, or making effective use of the various wastes mentioned above. It is preferable to contain this component component. Therefore, the starch used as the main raw material and the extender used as the extendable additive in the additive are collectively referred to as main solids.

In addition, if the extendable additive in the main solid content exceeds the content of starch, it is not preferable that the obtained biodegradable molding is made to be substantially not starch and the properties of the biomouldable molding are degraded. In addition, since the solid content of the functional additive is included in the "solid content" included in the molding raw material (see the graph in "(I) molding raw material" in FIG. 4), the starch and the extender are added together as the "main solid content". Express.

That is, in the present invention, when the total amount (main solid content) of the main solids (starch and extender) is 100% by weight, as shown in the graph of "(II) Main solid content of the total amount" of FIG. 4, starch (derivative) is included. ) Is in the range of 50% by weight or more and 100% by weight or less, and the extender is in the range of 0% by weight or more and less than 50% by weight (only 0 to 50% by weight in the drawings are described).

In addition, as shown in the graph horizontally in the "in the raw material for component (I)" of FIG. 4, the said main solids total amount will be 70 weight% or less when the whole raw material for shaping | molding to which water was added also makes 100 weight%. It is preferable.

In addition, as the content of each additive (which is a functional additive) in the additive contained in the molding raw material, and the content of each additive (which is a functional additive), as shown in "(I) molding raw material" of FIG. 4, water is also added. When making the whole raw material for shaping | molding used 100 weight%, it is more preferable to exist in the range of 0 weight% or more and 20 weight% or less. In addition, the addition amount of the functional additive in the case where the total amount of the main solids content is 100% by weight, that is, the amount of the functional additives relative to the total amount of the main solids content is not particularly limited as long as the final content in the molding raw material is within the above range.

That is, the functional additive may not be contained in the molding raw material in the same manner as the extender, but in order to improve the performance of the biodegradable molding in the present invention, the functional additive may be contained in 25% by weight or less in 100% by weight of the molding raw material. desirable. Moreover, when the functional additive contains more than 25 weight%, unless the function of the part corresponding to the content is exhibited, there exists a possibility that it may impair the function of a biodegradable molding in some circumstances, and it is unpreferable.

In the case where the main solids (starch + extender as the main raw material) and the functional additives are collected and used as raw material components, the molding raw material used in the present invention further contains water. The water mentioned here should just be water used for industrial use, and is not specifically limited.

As the content of water in the raw material for molding, as shown in the graph of "(I) molding raw material" in Fig. 4, when the raw material for molding is 100% by weight, it is within the range of 20% by weight to 70% by weight. Preferably, water is added so that it exists in the range of 25 weight% or more and 55 weight% or less.

In other words, as shown in the graph of "(III) raw material component and water contrast" in FIG. 4, when the total amount of the raw material component (main solid content + functional additives) is 100% by weight in the raw material for molding, water is 25% by weight. It is added in the range of% or more and 230 weight% or less, Preferably it is added in the range of 33 weight% or more and 120 weight% or less. If the water content is in the above range, the raw material for molding is in the form of slurry or dough.

If the content of water in the raw material for molding is less than 20% by weight, the water contained in the raw material for molding is so small that there is no fluidity at all, which is undesirable in molding. On the other hand, when it exceeds 70 weight%, since the content of the water contained in the shaping | molding raw material is too much, content of solid content will fall excessively and it cannot form sufficiently, it is unpreferable.

Since the molding raw material is in the form of slurry or dough, it is possible to easily fill the molding raw material into the cavity of the molding die as described later, and the molding processability is improved. In addition, it is possible to retain the water in the foamed molded product after molding, and to improve the flexibility of the foamed molded product as described later.

Moreover, in the said raw material for shaping | molding, in addition to the main raw material, additive, and water mentioned above, the additive other than that may be contained. Specific examples of the other additives are not particularly limited in terms of imparting any function to the biodegradable molding and appropriately selected.

In addition, the slurry form or kneading form described in this Embodiment is only classed conveniently based on the fluidity | liquidity of the raw material for shaping | molding, and has no relation with content of water. For example, the molding raw material to which water is added at a certain content is in the form of a slurry, and when the content of the water absorbing extender such as stabilizer or busy, or pulp is increased in the molding raw material, it becomes a dough. have. In the same way, the addition of a binder such as a protein may reduce the fluidity and may form a dough.

The above-mentioned foamed molded product is molded by using the above-described molding raw material, but the molding method may be a method using a molding mold having a cavity corresponding to the shape of a desired molded article and having at least two parts. . The said molding raw material is thrown in the cavity of the said molding die, and it heats and pressurizes and shape | molds the said foamed molded object.

Examples of the molding die include a structure in which at least two pieces of metal frames are made to be divided so as to extract the foamed molded product after molding.

As shown in Fig. 5 (a), Fig. 6 (a), and Fig. 7 (a), a mold 20a consisting of two metal pieces 21a and 22a of two pieces, a mold 20b made of pieces 21b and 22b, or a mold 21c. , A mold 20c made of 22c, or an upper mold 21d having the same shape as the mold 21c and a mold 22c in the lower direction, as shown in FIG. The mold 20d consisting of 23d and 24d mold pieces in the direction is exemplified by the mold.

That is, the molding die used in the present invention may be composed of a structure including a plurality of splittable mold pieces, and the method of division (that is, the number of mold pieces) is appropriately set according to the shape of the foamed molding. There is no limitation.

For example, in the said ball-shaped container 10a and the dish-shaped container 10b, since the magnitude | size of the wide direction planarly becomes large, the molding frame of two upper and lower parts like the said mold 20a and 20b is used preferably. On the other hand, in the case of the cup-shaped container 10c, a mold 20c having a vertically divided mold having a shape similar to the mold 20a or the mold 20b may be used. However, the cup-shaped container 10c has a size in the height direction compared to the ball-shaped container 10a or the dish-shaped container 10b. Since it becomes a large shape, the three division type like the metal mold | die 20d is used more preferably than the two division type like the metal mold | die 20c.

The molds 20a, 20b, and 20c are combined with the upper and lower mold pieces 21a, 21b, 21c, and 22a, 22b, and 22c, as shown in FIGS. 5 (b), 6 (b), and 7 (b). The cavity 25a, 25b, 25c which combined the shape of the desired foam molding (refer FIG. 1 thru | or 3) is formed inside. Similarly, the mold 20d is also formed such that the cavity 25d is formed as shown in Fig. 8 (b) in a state in which each of the mold pieces 21d, 23d, and 24d are combined.

In addition, although not shown, in the mold 20a, 20b, 20c, 20d, a hinge for movably connecting knockout pins or the frame pieces 21a to 21d, 22a to 22c, 23d, and 24d to select a foamed molding. ), A guide or a bar may be provided.

In addition, in the molded article used in the present invention as described below, heat resistance is required for steam foam molding, and at the same time, strength, friction resistance, and the like are also required. Moreover, microwave permeability is required when performing internal heating using a microwave. Therefore, in the internal heating using microwaves, a molded article made of a resin, a ceramic, or the like having microwave permeability, heat resistance, strength, friction resistance, and the like is used in the upward direction. In the case of internal heating using a high frequency dielectric, it is more preferable that it is made of metal "mold" so that it may act as a part of an upward electrode.

Examples of the heating means for the molding include, for example, external heating by direct heating means such as direct heating, far infrared rays, electric heaters, IH heating apparatuses, direct heating means for directly heating the molding mold, energization heating, high frequency dielectric heating, microwave heating, and the like. It is possible to use internal heating by internal heating means for heating it.

In the case of external heating, the mold (mold 20a, etc.) is directly heated by the direct heating means. Thereby, the molding raw material in the cavity (cavity-25a, etc.) is externally heated in the molding die, and the foaming material is molded by steam foaming of the above-mentioned forming raw material.

On the other hand, in the case of the internal heating, it is possible to use a shape similar to the above-mentioned mold for external heating. In this case, for example, as shown in Fig. 9, the mold 20a is taken as an example. , 22a, the electrodes 26, 26 for each of the pieces 21a, 22a are connected to each other, and an insulator 27 is arranged at the contact portion of each of the pieces 21a, 22a. It is possible to use the connected structure. Therefore, it is possible to internally heat the molding raw material filled in the cavity 25a. The electrode 26 is connected to a switch, a control circuit, or the like not shown in the other drawings besides the power supply 28.

In addition, the structure in which the electrode 26 is arranged in the frame piece 21a or the frame piece 22a can be applied to the case of the external heating. That is, even in the case of external heating, in order to directly heat the mold, the configuration shown in FIG. 9 such as the arrangement of the direct heating means and the electrode 26 can be modified in both the external heating and the internal heating.

Although it does not specifically limit as heating temperature in heat formation, In the case of external heating, it is preferable to heat a shaping | molding die within the range of 140 degreeC or more and 240 degrees C or less. If the heating temperature of the molding die is within the range, it is possible to sufficiently heat the raw material for forming the slurry or dough in the cavity (cavity 25a or the like) to obtain a molded product as a solid. In addition, when the temperature range is set to 100 ° C or higher boiling point of water, bubbles of water vapor generated by evaporation of water contained in the raw material for molding are necessarily generated. Therefore, the obtained molded article can be easily obtained.

On the other hand, in the case of internal heating, by applying a low frequency alternating current voltage or a high frequency electric field to the electrode 26, the raw material for molding in the cavity (cavity 25a, etc.) is upward, so that the heating temperature is also applied to various conditions related to the internal heating. It depends, and it does not specifically limit, What is necessary is just to exist in the temperature range in which the raw material for shaping | molding steam foams.

Specifically as the above various conditions, the characteristics of the electrode 26, the low frequency AC voltage and the magnitude of the high frequency electric field are largely involved, and as described above, it also greatly depends on the electrical conductivity and dielectric loss of the molding raw material. That is, when the heat-molding is performed by energizing heating, the heat generation state is controlled by the conductivity of the raw material for molding, and when heat-molding by high frequency dielectric heating, the heat generation state is controlled by the dielectric loss of the raw material for molding. to be.

About the specific setting range of the said various conditions, what is necessary is just to set so that the temperature in a cavity may be in the temperature range similar to external heating practically, and is not specifically limited.

In the above heating time, it is preferable that there is a time in which the moisture content of the foamed molded product after the molding is settled within a predetermined range as appropriately set for the heating temperature and the shape and thickness of the foamed molded product. In other words, it is preferable to be at a time which hardly evaporates the water in the molding raw material.

When the heating time is left for a long time in the water direction of the foamed molding to be smaller than a predetermined range to be described later, the foamed molded article does not have a predetermined moisture content as long as it is in an excessively foamed state, so that the foamed molded product is hard and brittle. It is not good because it lowers.

Specifically, the heating time is not particularly limited. For example, in the case of performing high frequency dielectric heating, it is generally possible to mold in a much shorter time than external heating, and when the foamed molded article has a thickness, the heating time tends to be long. Therefore, it is preferable to specifically set a heating time suitably by the heating method, the shape of a foamed molding, etc., and to exist generally in the range of 10 second or more and 5 minutes or less.

Although it does not specifically limit also in pressurization at the time of heat forming, Generally, the inside of the range of 5 kg / cm <2> or more and 50 kg / m <2> is used preferably, for example. Of course, the molding pressure can be changed according to various conditions.

As shown in Figs. 10 (a), (b) and (c), the raw materials for molding in the cavities 25a, 25b, 25c and 25d using the molds such as the molds 20a, 20b, 20c and 20d are heated and pressurized. As the foamed molded product, a ball-shaped container main body 11a, a dish-shaped container main body 11b, or a cup-shaped container main body 11c is obtained, but these foamed molded products have a final water content after molding in a range of 3% by weight to 20% by weight or less. Preferably it is in the range of 3 weight% or more and 15 weight% or less.

If the final moisture content is less than 3% by weight, the moisture content is too low, the foamed molding becomes hard and brittle, and the flexibility is lowered, which is undesirable. On the other hand, if the moisture content exceeds 20% by weight, the moisture content is too high, the foamed molded article is more than necessary moisture, the weight increases, it is difficult to adhere or adhere to the coating film 12 is not preferable.

As described in the description of the moisturizer, the molded article obtained by simply α-forming starch is stiff and brittle, and its use is very limited. Here, in the present invention, the water content of the obtained foamed molded product can be set within the above-mentioned range only by molding, in order to sufficiently contain water as a slurry or dough form. In addition, if the water content according to the molding conditions or other conditions are slightly out of the above range, in this case, the water content by placing the foamed molding within a certain humidity for a certain time, spraying water and standing in the drying range for a certain time. It is possible to adjust.

In the biodegradable molded article shown in the present invention, a coating film 12 made of biodegradable plastic is attached to the surface of the foamed molded article (such as the base 11a). That is attached. That is attached. It has at least hydrophobicity, and by attaching to the foamed molded article, it is possible to impart at least water resistance to the foamed molded article. In addition, the coating film is attached. Furthermore, it is more preferable to provide gas impermeability, heat insulation, wear resistance, improvement of strength, flexibility, and the like.

In particular, when the biodegradable molded article shown in the present invention is used in a high-sealing storage container or the like, it is necessary to avoid oxidation or moisture of the accommodating body contained therein, so that the coating film 12 can impart gas impermeability, That is, it is very preferable to have gas impermeability.

In addition, especially when using the biodegradable molded article shown in the present invention as a cup-type container or the like, it is necessary to avoid deformation or melting of the biodegradable molded article by the heat of the contained water contained therein, so that the coating film 12 has a gas impermeability. It is preferable to be able to provide, ie, to have high heat resistance. Specifically, the coating film 12 preferably has a soft start temperature of 130 ° C. or higher, and more preferably a soft start temperature of 150 ° C. or higher. Moreover, it is preferable that melting | fusing point is 170 degreeC or more, and, as for the covering film 12, it is more preferable that melting | fusing point is 200 degreeC or more. In addition, it is particularly preferable that the coating film 12 has a softening start temperature of 130 ° C or higher and a melting point of 170 ° C or higher, and particularly preferably a softening start temperature of 150 ° C or higher and a melting point of 200 ° C or higher. 12 such as the heat of the contained product contained inside these can impart gas impermeability, that is, it is possible to avoid deformation or melting of the biodegradable molding.

The raw material of the coating 12 is not particularly limited as long as the material can exhibit at least water resistance, preferably gas impermeability, after being adhered to the surface of the foamed molded product so as to exhibit biodegradability.

Specifically, for example, 3-hydroxybutyl acid-3-hydroxy valeric acid copolymer, poly-p-hydroxybenzaldehyde (PHB), polybutylene susinate (PBS), polycaprolactone (PLC), Acetyl cellulose (PH) polymer, polyethylene susinate (PESu), polyester amide, modified polyester, Mother-B (registered trademark, Italy, Nomarmont, Inc .: starch based biodegradable polyvinyl alcohol series) Gina aliphatic polyester series 12 is a variety of materials known as so-called "biodegradable plastics", such as those that can impart gas impermeability, that is, as a minor component, cellulose and chitosan composites. One type of these raw materials may be used and two or more types of composites may be used. As these biodegradable plastics, additional raw materials such as biodegradable plasticizers and fillers may be added.

In addition, you may prepare the coating film 12 which mixed the starch for each said raw material (biodegradable plastic). In this case, the mixing ratio of the biodegradable plastic to starch is not particularly limited as long as the hydrophobicity of the coating film 12 does not degrade various functions, but it is possible to preferably use a mixing ratio of about 1: 1 weight ratio, for example.

In addition, in the coating film 12, various additives may be added. As a specific additive, for example, a colorant, an additive obtained by improving water resistance, gas impermeability, etc., an additive which improves various characteristics in softening at the time of adhesion, etc. are exemplified, and are not specifically limited.

Although the thickness (film thickness) of the said coating film 12 is not specifically limited, What is necessary is just to consist of a film or sheet in the range of 0.01 mm or more and several mm or less before it adheres to a foamed molding.

Furthermore, since the coating film 12 adheres to the surface of the foamed molded product which is heated and softened as described later, the thickness after the adhesion is thinner than in the above range. Although the thickness of the coating film 12 after this adhesion | attachment is suitably set to the thickness which can exhibit water resistance, gas impermeability, etc. with respect to the kind of biodegradable plastic which is a raw material, although it does not specifically limit, Preferably the upper limit is 80 It is micrometer or less, More preferably, it is 50 micrometers or less. Also in the lower limit, any thickness may be sufficient to exhibit the above water resistance, gas impermeability, and the like, but generally 5 µm or more is preferably used.

In the biodegradable moldings shown in the present invention, the weight occupied by the foamed moldings in the total weight is preferably 60% by weight or more. That is, in the biodegradable moldings shown in the present invention, it is preferable that the occupied weight of the biodegradable plastic in the total weight is at least 40% by weight.

As described above, biodegradable plastics have a lower biodegradation rate than starch. Specifically, when the biodegradation rate of the foamed moldings containing starch as a main component is 1, the biodegradation rate of the biodegradable plastics of the same weight is different from that of the biodegradable plastics, and the film is generally different. It can be said that it is in 1 range.

To this end, if the amount of biodegradable plastic contained in the biodegradable molding is too large, even if it has some degree of biodegradability, the biodegradability as a whole of the biodegradable molding is insufficient. Therefore, in order to exhibit more excellent biodegradability, it is highly desirable to define an upper limit of the amount of biodegradable plastics in the total weight.

As a result, the biodegradable molded article shown in the present invention must have the coating film 12 as a biodegradable plastic, and biodegradable plastic may be used as an adhesive (adhesive layer 13) described later. As a result, the upper limit of the amount of the biodegradable plastics defines the upper limit of the amount of the coating film 12 and the adhesive layer 13.

However, the adhesive 13 does not necessarily need to be used (for example, a ball-shaped container 10a shown in FIG. 1 (a)), and as the adhesive layer 13, a non-plastic natural material made of a starch-based film is used as described later. It is also possible. Here, as the biodegradable molded product shown in the present invention, the amount of the foamed molded product mainly made of starch is defined to define the amount of the biodegradable plastic.

In the biodegradable moldings shown in the present invention, the biodegradable plastics are easily decomposed so that the coating film 12 or the adhesive layer 13 is filmed. As described above, the occupied weight of the foamed molding is 60% by weight or more, so that at least the weight of the biodegradable plastic (coating film 12 or adhesive layer 13) is specified to less than 40% by weight. As a result, the biodegradation balance between the biodegradable plastics and the foamed molding is good, and therefore, it is possible to further improve the biodegradability of the biodegradable moldings.

In particular, the foamed molded product is a foam and has good biodegradability. However, the content of the coated film 12 and the adhesive layer 13 corresponding thereto can be suppressed, so that the foamed molded product can exhibit very good biodegradability as a whole. To this end, when using the biodegradable moldings shown in the present invention as a food tray or the like, no problem occurs even when mixed with food residues.

In the biodegradable moldings shown in the present invention, the occupied weight of the foamed moldings in the total weight is preferably 60% by weight or more. That is, in the biodegradable moldings shown in the present invention, it is preferable that the occupied weight of the biodegradable plastic in the total weight is at least 40% by weight.

In the present invention, the coating film 12 is attached to the structure directly bonded to the foamed molding by the method for producing a biodegradable molding (see Fig. 1 (a)), and the adhesive layer 13 is sandwiched and attached (example For example, there are two types (see Fig. 1 (b)), but in the latter configuration, an adhesive to attach the coating film 12 is required.

The adhesive is not particularly limited as long as it is biodegradable and capable of attaching the coating film 12 to the foamed molding at the same time. Specifically, for example, various kinds of natural binders or binders containing starch or protein as a main raw material, and PVA in these Aqueous adhesives such as mixing (polyvinyl alcohol); Proteins that are poorly or insoluble in water and hardened by heat denaturation; Low melting point adhesives such as low melting point biodegradable plastics (generally synthetic) and mixtures thereof meltable at or below the melting point of the coating film 12; Thermosetting adhesive having fluidity at room temperature; Etc. are examples.

The aqueous adhesive is mainly natural, and in particular, a material such as starch similar to a foamed molded article has an advantage of being excellent in biodegradability or safety due to the film. The method of using the water-based adhesive is not very limited, but may be applied to the surface of the foamed product by using a brush or the like, and then coated on the surface of the foamed product after the coating film 12 is applied or, alternatively, the surface of the coated film 12 is applied.

As the low melting point adhesive, it is possible to use a low melting point biodegradable plastic (general synthetic product), a mixture thereof, and the like which can be melted at the melting point or less of the coating film 12. That is, in the biodegradable plastics, for example, the melting point is lower than that of the biodegradable plastics selected from the cover film 12 forming the outermost layer, specifically, at a temperature lower than the softening point of the cover film 12, or coated. Melting at a temperature below the melting point of the softening point of the film 12 may be appropriately selected and adopted.

For example, when using the film containing polylactic acid or modified polyester as a main component as the coating film 12, these softening points are in the range of 80 ° C to 100 ° C, and the melting point is 60 ° C to It is possible to preferably use polycarpolactone at 70 ° C.

The low melting point biodegradable plastic is usually used in the form of a film. That is, it is very preferable to use the low melting point biodegradable plastic as an adhesive film. As will be described later, since the coated film 12 is heated and press-pressed to the foamed molding rather than the adhesive, the coated film 12 is heated and pressurized when the adhesive film made of low melting point biodegradable plastic is inserted into the coated film 12 and the foamed molding. The low melting point biodegradable plastics are dissolved, so that they can be used as good adhesives.

It is preferable to contain the said aqueous adhesive agent and the low melting-point biodegradable plastics, and to use the adhesive for this invention, which does not use the volatile organic solvent. In the case of using the organic solvent, it is necessary to provide an apparatus for preventing the diffusion of the organic solvent volatilized in the bonding process of the coating film 12, and therefore, the manufacturing equipment is enlarged, which is not preferable.

Next, a description will be given of a method for producing a biodegradable molding shown in the present invention.

As a method for producing the foamed molded article shown in the present invention, first, the molding raw material can vaporize the foamed molded article having a predetermined shape, and then the coating film is attached (called a post-adhesive method), and simultaneously with the steam foam molding of the molding raw material. There are two kinds of methods for attaching the coated film (called simultaneous attachment method).

First, a description is given of the post-attachment method. This post-attachment method is a molding process of steam foaming a predetermined shaped foamed molded article (vessel main bodies 11a, 11b, 11c, etc.) from at least the raw material for molding, and heating and softening the coating film 12 to compress the foamed molded article. It includes two steps of the attachment process to attach. The biodegradable moldings obtained by this method are prepared by applying the adhesive layer 13 between the coating film 12 and the foam moldings (container bodies 11a, 11b, 11c) as shown in Figs. 1 (b), 2 (b), and 3 (b). A configuration is included.

As a result, it is possible to obtain a biodegradable molded article having stably adhered the coating film 12 to the main body (foamed product) having a stable moisture content while being obtained by retaining a moisture content that can exhibit sufficient strength at the time of molding.

Here, in the case of attaching the coating film 12, an attachment frame having a shape substantially the same as that of the molding die (mold 20a, etc.) used for molding the foamed molded article is used. For example, when the coating film 12 is attached to the container body 11a made of the ball-shaped container 10a, as shown in Fig. 11, a mold 30 having a shape substantially the same as the mold 20a is used.

The shape of the attachment frame does not need to be completely consistent with the appearance of the foamed molding, and may be a shape capable of inducing the coating film 12 in a process of sufficiently adhering to the surface of the foamed molding. What is necessary is just to copy (copy) a mold. As a result, it is possible to produce an attachment mold at a low cost and at the same time, it is possible to attach 12 kinds of coated films that are reliable and easy even in a complicated molded foam. As a result, a biodegradable molding can be manufactured by a simpler process.

The shape of the attachment frame is not particularly limited as long as it has a cavity having the same shape as that of the molding die. However, in the case of attaching two layers of the covering film 12 and the adhesive film, in order to reliably melt the adhesive film, It is equipped with heating means similar to Therefore, for example, in the attachment of the coating film 12 in the case of manufacturing the ball-shaped container 10a, it is possible to use the mold 20a as shown in Figs. 5 (a), (b) or 9 as it is as the attachment frame.

As a specific example, as shown in Fig. 11, first, the entire ball-shaped container 11a is disposed as a foamed molding with respect to the mold 30, and at the same time, a position corresponding to the surface to which the covering film 12 is to be attached in the container main body 11a. Place covering film 12 on the substrate.

In FIG. 11, in order to apply the coating film 12 to the entire foamed molding, the coating film 12 is placed on the frame 32 of the lower part of the mold 30, the container body 11a is placed thereon, and the coating film 12 is further placed thereon. The mold of the upper part of the mold 30 is further arrange | positioned on it. Therefore, the container main body 11a is arrange | positioned as if sandwiched between two coating films.

In addition, when the low melting point biodegradable plastic is employed as the adhesive, an adhesive film 13a made of this is disposed between the covering film 12 and the container body 11a as shown in FIG. In other words, the coating film 12, the adhesive film 13a, the container body 11a (foamed product), the adhesive film 13a, and the coating film 12 are placed in this order on the lower frame 32. In addition, in FIG. 11, the space | interval is described between films and molded films for convenience of description.

Thereafter, as long as the temperatures of the mold pieces 31 and 32 are set to a temperature lower than the softening point of the coating film 12 or lower than the melting point, the upper mold pieces 31 and the lower mold pieces 32 are combined up and down, and the respective mold pieces 31, The cover film 12 is affixed on the surface of the container main body 11a by squeezing the pressure suitably to 32. At this time, since the adhesive film 13a melts at the temperature below the softening point of the coating film 12, the melted adhesive film 13a is fused to the surface of the container main body 11a, and it becomes the adhesive bond layer 13, and the coating film 12 is affixed on it.

In addition, when the biodegradable plastic which melts at a temperature lower than the softening point of the coating film 12 or lower than the melting point is employed as the adhesive film 13a, the heating temperature of each of the pieces 31 and 32 must also be set to a temperature higher than the softening point of the coating film 12 or lower. There is.

The pressure at the time of adhesion of the coating film 12 is appropriately selected depending on the type of adhesive to be used, but is not particularly limited, but preferably a high pressure is applied to reduce the thickness of the foamed molding. Thereby, the adhesiveness of the coating film 12 along the adhesive bond layer 13 becomes favorable, The thickness of the biodegradable molding (ball container 10a in FIG. 1 (b)) in a final molding is also good, and stackability (stackability) It is possible to improve) (easiness of cup lamination | stacking and the number of cups at the time of laminating | stacking a cup to predetermined height).

In the manufacturing method shown by this invention, when employ | adopting a post-attachment method, it is especially preferable to employ | adopt the adhesive film 13a as an adhesive agent for attaching the coating film 12 as mentioned above. In this method, since the adhesive film 13a has to be disposed before the coating film 12 is attached, a process for applying the adhesive on the surface of the foamed molding is not necessary, which makes it possible to further simplify the manufacturing method of the biodegradable molding.

That is, since the foamed molded article (container main body 11a etc.) which becomes the main body of the biodegradable molding shown by this invention has starch as a main component and has a constant water content, it is clearly hydrophilic. On the other hand, the coating film 12 is hydrophobic as mentioned later. Therefore, even if the coating film 12 of the foamed molding is simply matched in the post-adhesion method, there is a high possibility that it will not sufficiently adhere to the foamed molding.

When the coating film 12 using the said adhesive film 13a is adhere | attached on this, as shown in FIG. 12 (a), the coating film 12 is reliably attached by interposing the adhesive layer 13 with respect to the hydrophilic foamed molding 11. As a result, it is possible to further improve the water resistance and gas impermeability which stabilized the adhesion state of the coating film 12 in the biodegradable molding shown by this invention.

In addition, in the said post-bonding method, what was previously shape | molded by the coating film 12 used by the co-adhesive method mentioned later as a molded film, a film piece, or an outline frame film etc. nearly matched with the external shape of the obtained biodegradable molded object is used. It is possible to do

In this way, if the coating film is first molded into a shape almost conforming to the appearance of the biodegradable molding, the coating film is not torn in the attachment process. To this end, it is possible to mold well a biodegradable molding having a deep drawing shape. In the said molding film, a film piece, an outer frame film, etc., an outline frame is explained in full detail.

Next, the outline is described. This simultaneous bonding method includes at least a molding-simultaneous-adhering step of attaching the coating film 12 to the water vapor molding frame at the same time as described above. The biodegradable moldings obtained by this method have a coating film 12 directly formed on the surface of the foam moldings (container bodies 11a, 11b, 11c), as shown in Figs. 1 (a), 2 (a), 3 (a), and the like. It is structured. This co-adhesion method has the following advantages when compared with the post-adhesion method described above.

First, as a first advantage, it is possible to reduce the number of processes. That is, since the co-adhesion method can adhere the coating film 12 in one practical step, at least two steps can reduce the number of steps compared with the necessary post-attachment method. In addition, it is also possible to shorten the time required for manufacture since the adhesion is possible in one step. Therefore, it is possible to improve the production efficiency of the biodegradable moldings shown in the present invention.

As a second advantage, there is no need to use an attachment frame. That is, in the co-adhesion method, the foaming mold (container main body 11a, etc.) is molded more than in the molding die (mold 20a, etc.) and at the same time, there is no need for an attachment mold (such as mold 30 shown in Fig. 11) for attaching the coating film 12. To this end, it is possible to reduce the cost according to the manufacturing equipment, and at the same time, it is possible to achieve a miniaturization of the manufacturing equipment because the installation equipment including the attachment frame also has the attachment frame.

As a third advantage, there is no need to use an adhesive. That is, in the simultaneous bonding method, since the coating film 12 attachment frame is bonded at the same time as the molding, the coating film 12 is attached in a state almost attached to the surface of the foamed molded article (such as the container body 11a). Therefore, the raw material cost of an adhesive part can be suppressed, and the content rate of starch in the biodegradable molding obtained by use of an adhesive agent can be raised, and biodegradability can be improved further.

As a fourth advantage, since the coating film 12 attachment frame is almost in close contact with the foamed molded product, the coating state of the coating film 12 becomes stable in the same level as the post-attachment method using the adhesive film 13a. .

That is, as described above, the foamed molded article such as the container body 11a is hydrophilic, whereas the coated film 12 is hydrophobic, and thus, even if the coated film 12 of the foamed molded article is simply matched, there is a high possibility that it will not sufficiently adhere to the foamed molded article.

However, in the co-adhesion method, the coating film 12 is attached at the same time as the water vapor foam molding of the raw material for molding at least at the softening point or more than the melting point of the biodegradable film serving as the main component of the coating film 12. To this end, the coating film 12 faces a heated and pressurized state of the foamed molding in the foam molding process, receives the pressure from the outside in the softened state, and continues the pressure of the foamed molding in the foam molding process inside. It is in close contact with the foamed molded article. As a result, the coating film 12 attachment frame is matched in a shape such as fusion welding on the surface of the foamed molding.

Accordingly, in the cross-section of the biodegradable molding obtained as shown in Fig. 12 (b), when the interface 15 between the layer of the covering film 12 and the surface of the foamed molding 11 is simply attached (the post-attachment method shown in Fig. 12 (a)). It may not be a smooth surface as shown in (), and becomes, for example, an irregular surface with irregularities, so that the coating film 12 is in a state of being in close contact with the foamed molding 11. As a result, the adhesion state of the coating film 12 becomes very hard, and the stability of the adhesion state is also the same level as when the adhesive layer 13 is provided. Therefore, the water resistance and gas impermeability of the obtained biodegradable molding can be further improved.

12 (b), the interface 15 between the layer of the covering film 12 and the surface of the foamed molding 11 is schematically represented by, for example, an irregular surface with irregularities, but is not limited thereto. The boundary surface of various shapes is obtained by 12 conditions, the components contained in the foamed molded product 11, or the conditions etc. by the co-adhesion method. Therefore, in the present invention, in the biodegradable molded article obtained by the co-adhesion method, the layer of the coating film 12 and the foamed molded article 11 may be in a state of being almost completely in close contact.

The advantages of the above 4 are that, in combination with the post-adhesion method, it is possible to produce the biodegradable moldings shown in the present invention which are more effective than the post-adhesion method and have similar characteristics to the post-adhesion method at a lower cost. It is possible to provide at low cost. Therefore, it is possible to make the biodegradable moldings shown in the present invention easier to use than to use them in a single use.

However, depending on the kind of coating film 12, the composition of a molding raw material, etc., it may be difficult to implement a simultaneous adhesion method, and in that case, a post-adhesion method is used very preferably. That is, there are advantages in the post-attachment method and the simultaneous adhesion method, and each of these methods is appropriately selected according to the situation. Therefore, any method has excellent characteristics as a method for producing the biodegradable moldings shown in the present invention.

In the co-adhesion method, the coating film 12 is softened at a temperature higher than the softening point below the melting point at the same time as the steam foam molding of the raw material for molding, and the coating film 12 is attached at the same time as the molding of the molded foam. Therefore, it is necessary to appropriately select the conditions of the heating means for the coated film 12 used.

In other words, it is necessary to select the coating material 12 whose main melting point is 100 deg. . If the coating film 12 has a biodegradable plastic having a melting point of 100 ° C. or less as a main component, the coating film 12 is completely melted at a temperature for sufficiently forming the steam for molding the raw material for molding. To this end, the coating film 12 cannot maintain the film state or the sheet shape, and thus a uniform layer of the coating film 12 without spaces or holes is not formed on the surface of the foamed molded product.

On the other hand, even when internal heating is used as the heating means, it is preferable that the coating film 12 has a melting point of 100 deg. However, it is possible to use a relatively low melting point compared to the external heating.

In the case of internal heating, the molding raw material itself is heated. Thus, the coating film 12 is adhered to the surface of the heated molded article by the hot forming raw material in the foam molding process. Therefore, since internal coating does not directly heat the coating film 12 with a mold, it becomes possible to use the coating film 12 mainly composed of a biodegradable plastic having a relatively low melting point.

In the internal heating, dielectric heating is particularly preferred. In the case of dielectric heating, the molding raw material generates heat in a short time at the initial stage of coating molding, and the whole expands constantly. As a result, the pressure suppressed by the coating film 12 in the mold is strong and uniformly generated. In addition, by controlling the temperature of the mold and the heat generation of the raw material for molding, the temperature of the mold contact surface (surface connected from the mold) to the coated film in the coated film is kept below the melting point, and the adhesive surface in the foamed molding It is also possible to raise the temperature of the surface (bonded with the coated film) near the melting point. As a result, a biodegradable molded article having high adhesion between the foamed molded article and the coated film 12 can be obtained.

In the above-mentioned dielectric heating, in the method of heating the to-be-tested object by the dielectric loss of the to-be-tested object, the microwave heating or the heating of the to-be-treated material (dielectric) is performed by applying high frequency (HF; 3 to 30 MHz) of the to-be-heated material (dielectric). Microwave heating such as dielectric heating by applying microwave (HF; 1 to 100 GHz). Among these, high-frequency dielectric heating can perform dielectric heating using a metal "mold" as an electrode. It is more preferable at the point that the heat generation of the raw material for shaping | molding is easy to control in order to enable the precise output control of an output device (high frequency generator).

On the other hand, in the external heating, since the coating film 12 is directly heated by the molding die, the molding raw material therein is further heated, so that the coating film 12 is subjected to a considerably high heat in order to sufficiently foam the molding raw material. For this purpose, it is preferable to use a higher melting point as the coating film 12, and the heating temperature of the molding die must be set in more detail in consideration of the melting point and the softening point of the coating film 12.

Therefore, in the co-adhesion method, it is easy to attach and in view of the choice of the coating film 12, etc., the internal heating method is more versatile as the heating method in the co-adhesion method.

However, in the external heating, since the coating film 12 is directly heated in the molding die, there is an advantage that it is easy to control the softening of the coating film 12 and the adhesion on the surface of the foamed molding. In addition, in the case of the coating film 12 having a high softening point, internal heating is used, and the raw material for molding is heated to the extent that the coating film 12 is softened sufficiently. Since the quality of a molded object may fall, external heating may be preferable. As described above, since the heating method has advantages of both external heating and internal heating in the simultaneous bonding method, the heating method is based on which biodegradable moldings are to be used, whether to use external heating, internal heating, or the like. It does not specifically limit based on conditions selected suitably, such as whether to use together.

In the co-adhesion method, it is possible to classify, for example, into the following seven types (eight types including deformation) by the method of using the coated film 12 at the time of adhesion.

[Preparation 1]

In the post-adhesion method, in the post-adhesion method, the raw material for molding is inserted between the uncoated sheet-like coated film 12, and the water vapor foam molding is carried out in a molding mold. It is a method of attaching the coating film 12. This manufacturing method is particularly preferably used for forming a biodegradable molding having a large size in a direction flattened in accordance with a sheet-like covering film 12, like the dish-shaped container 10b shown in Fig. 2 (a). It is possible.

Specifically, this production method 1 will be described. As shown in Fig. 12, in the mold 20 shown in Figs. 6 (a) and 6 (b), 12 melting points or two sheets of the coated film in the form of sheets are arranged between the upper and lower pieces 21b and 22b. It arrange | positions and supplies the raw material 14 for shaping | molding of a slurry form or a dough form between these coating films 12 and 12 further. In this state, the mold 20b is heated to a temperature below the melting point of the biodegradable plastic which is the main component of the coating film 12. Thereafter, the upper and lower mold pieces 21b and 22b are combined and heated and press-molded using the above-described external heating or internal heating. By this one step, it is possible to obtain a dish-shaped container 10b (see Fig. 2 (a)) which is the biodegradable molded product shown in the present invention.

[Method 2]

The manufacturing method 2 is a method in which the coating film 12 used in the said manufacturing method 1 is shape | molded previously in the shape substantially matching the external shape of a biodegradable molding. This production method can be suitably used for the purpose of forming a biodegradable molded article having a certain stretched shape, that is, a shape having a large size in the height direction, such as the ball-shaped container 10a shown in Fig. 1 (a).

The coating film 12 includes a biodegradable melting point and a kind that are the main components, but include a melting point and an unstretchable at the time of molding. For this purpose, for example, in the case of forming a biodegradable molded article having a depth of elongation as shown in a ball-shaped container 10a as shown in Fig. 1 (a), when the above method 1 is used, the coating film 12 is torn to sufficiently expand the foamed molded article. There is a possibility that it cannot be covered. Thus, the molded film formed by forming the covering film 12 close to the appearance after molding in advance is prepared. Thereby, the coating film 12 with respect to the foamed molding of a more complicated extending | stretching shape is reliably and effectively coat | covered.

In the forming method of the coating film 12, a general forming method of a sheet film is used, and is not particularly limited, but various forming methods such as vacuum molding, injection molding, blow molding and the like are preferably used. In addition, in the shaping | molding shape, it should just be substantially matched with shaping | molding of a biodegradable molded object after shaping | molding, and it does not need to shape | mold to a specific part similarly. Since the covering film 12 has some flexibility, the approximate shape should just match the shape of the biodegradable molding after shaping | molding, ie, the shape of a shaping | molding die.

Specifically, the manufacturing method 2, as shown in Fig. 14, almost coincides with the outside of the ball-shaped container 10a between the upper and lower pieces 21a and 22a for the mold 20a shown in Figs. 5 (a) and (b). 2 pieces of the molded film 12a previously molded are placed, and the raw material 14 for forming a slurry or dough is further supplied between the molded films 12a and 12a. In this state, the said mold 20a is heated to the temperature below melting | fusing point of the biodegradable plastic which is a main component of the shaping film 12a (coating film 12). Thereafter, upper and lower mold pieces 21a and 22a are combined and heated and press-molded using the above-described external heating or internal heating. By this one step, a ball-shaped container 10a (see Fig. 1 (a)) can be obtained as the biodegradable molded article shown in the present invention.

[Process 3]

The manufacturing method 3 is a method in which the coating film 12 used in the said manufacturing method 1 is processed into the bag shape, and the raw material for shaping | molding is accommodated in this bag-shaped coating film 12. Like the dish-shaped container 10b shown in Fig. 2 (a), this manufacturing method is also suitably used for the purpose of forming a biodegradable molding having a large size in a planar wide direction in conformity with the sheet-shaped covering film 12. have.

In this manufacturing method, the covering film 12 is processed into a bag shape so as to accommodate the molding material therein, and is made into a bag film. If the raw material for molding is placed inside the bag film, the raw material for molding is almost packed into the bag film. Therefore, a large amount of the raw material for molding in the bag film can be prepared in advance and stored for a certain period of time. Become. Further, at the time of producing the biodegradable molding, preparation of molding is completed by simply putting the raw material package in the molding mold at once. Therefore, there is an advantage that the manufacturing process can be further simplified.

The method for processing the coated film 12 into a bag-shaped bag film is not particularly limited, but a conventionally known method for processing a sheet or film-shaped plastic into a bag shape is suitably used. Specifically, a pillow packaging etc. are mentioned. In addition, the preservation method of the raw material package which divides and injects the molding raw material in a packaging film is not specifically limited, either, A conventionally well-known maintenance method which does not rot starch may be sufficient.

Moreover, in this invention, what accommodates the raw material for shaping | molding in the said bag film 12b becomes "a composition for foaming shaping | molding." The composition for foam molding (hereinafter, referred to as molding composition) can be prepared as long as it is added in advance as described above and stored for a certain period of time. It is possible to easily produce attached biodegradable moldings. For this purpose, it is suitable as a composition for producing a biodegradable molding in an easy and simple process.

The manufacturing method 3 of this invention is demonstrated concretely. As shown in FIG. 15, the coating film 12 is previously processed into the bag shape, it is set as the bag film 12b, the predetermined amount of shaping | molding raw materials 14 in this bag film 12b are divided | segmented, and the composition for shaping | molding Prepare 40b. The molding composition 40b may be stored in a predetermined warehouse or the like. Thereafter, in the mold 20b shown in Figs. 6A and 6B, the molding composition 40b taken out of the warehouse is stacked on the lower frame 22b. This completes the molding preparation.

In this state, the said mold 20b was heated to the temperature below melting | fusing point of the biodegradable plastic which is a main component of the coating film 12 (packaging film 12b). Thereafter, the upper and lower mold pieces 21b and 22b are combined and heated and press-molded using the above-described external heating or internal heating. By this one step, it is possible to obtain a dish-shaped container 10b (see Fig. 2 (a)) as the biodegradable molded article shown in the present invention.

[Process 4]

The manufacturing method 4 was the method of combining all the said manufacturing methods 1, 2, and 3, and the coating film 12 used was shape | molded in the shape which was previously made into the bag shape and nearly matched with the external shape of a biodegradable molding. That is, in the manufacturing method 3, the bag 12d consists of a molded bag film of the shape which almost matches the external shape of a more biodegradable molding. This manufacturing method can also be used suitably for the purpose of forming the biodegradable molded object of the shape extended deeply to some extent, ie, the shape of the height direction large like the ball-shaped container 10a etc. which are shown to Fig.1 (a).

The molded bag film may be formed by first coating the coating film 12 into a bag-shaped packaging film and substantially conforming to the appearance of the biodegradable molding, or may be processed into a packaging film from molding almost conforming to the external appearance. The molding method and the processing method in the packaging film are also not particularly limited, but a conventionally known method is suitably used as described above.

The manufacturing method 4 is specifically demonstrated, as shown in FIG. 16, the coating film 12 was shape | molded in the shaping | molding bag film 12c, and the shaping | molding composition 40c which divided the predetermined amount of raw materials for shaping | molding in this shaping bag film 12c was prepared, Put it. The molding composition 40c may be stored in a predetermined warehouse or the like. Thereafter, in the mold 20a shown in Figs. 5 (a) and 5 (b), the molding composition 40c from the warehouse is placed on the lower piece 22a. This prepares the molding.

In this state, the said mold 20a is heated to the temperature below melting | fusing point of the biodegradable plastic which is a main component of the coating film 12 (molded bag film 12c). Thereafter, upper and lower mold pieces 21a and 22a are combined to be heated and press-molded using the above-described external heating or internal heating. By this one step, it is possible to obtain a ball-shaped container 10a (see Fig. 1 (a)) as the biodegradable molded article shown in the present invention.

[Method 5]

In the manufacturing method 5, in the said manufacturing method 1, it is the method of using the coating film 12 cut | disconnected in the shape substantially matching the external shape of a biodegradable molding previously. This manufacturing method can be used suitably for the use of shape | molding a biodegradable molded object of a shape with a deep drawing degree, or a more complicated shape like the cup-shaped container 10c shown to Fig.3 (a).

Although the specific shape of the said film piece is not specifically limited, Usually, as shown to FIG. 17 (a), (b), each surface is a rough starting figure of the biodegradable molding (for example, cup-shaped container 10c) after shaping | molding. The method placed in the some film piece 12d cut out every time is used preferably.

As shown in Figs. 17A and 17B, the film piece 12d further has an overlapping portion 12e equivalent to the overlapping portion. This overlap part 12e is attached to the end etc. which were adhere | attached when the film piece 12d which forms the periphery or side surface of the film piece 12d which forms a bottom surface is enclosed in cylindrical shape.

When these overlapping part 12e arrange | positions the film piece 12d in the cavity of a shaping | molding die at the time of shaping | molding, each film 12d overlaps each other in a predetermined | prescribed site | part. Therefore, at the time of shaping | molding, the overlap part 12e and the part of the film piece 12d which overlap this are adhere | attached flexibly (welding). As a result, a plurality of film pieces 12d are brought together into a nearly cup-shaped covering film 12, and the covering film 12 further matches the surface of the foamed molded product, whereby the cup-shaped container 10c shown in the present invention is obtained.

In addition, the shape of the film piece 12d is not particularly limited as a developed view. However, as shown in Fig. 17 (a), for example, the case where the film piece 12d meets the size 10c is set to one film piece 12d, respectively. The developed view may be divided into two sides by the side and the bottom, and as shown in Fig. 17B, the bottom may be divided into two, and as shown in Fig. 17B, the bottom may be one. The three film pieces 12d which divided the side into two may form the shape corresponding to the biodegradable moldings, such as cup shape, in the state which overlapped the whole overlapping part 12e.

In this manufacturing method, the coating film 12 before adhesion | attachment is set to the shape more suitable for the molded object after shaping | molding than the said manufacturing method 2 or the manufacturing method 4. Therefore, this manufacturing method uses a coating film 12 mainly composed of poorly degradable biodegradable plastics, in particular to form a biodegradable molding having a deeply stretched shape, such as the cup-shaped container 10c, with a covering film 12 having poor stretchability. In this case, the thickness of the coated film 12d after adhesion can be effectively used.

Specifically, the manufacturing method 5, in the mold 20d shown in Figs. 8 (a) and (b) as shown in Fig. 18, the bottom of the cup-shaped container 10c according to the shape of the cavity of the lower mold pieces 23d and 24d. The film piece 12d corresponding to the film piece 12d and the film piece 12d corresponding to the side surface are arranged. At this time, the overlap part 12e is reliably overlapped.

By the way, the raw material 14 for shaping | molding is further provided with respect to the nearly cup-shaped film piece 12d. On the other hand, a film piece 12d corresponding to the bottom of the cup-shaped container 10c and a film piece 12d corresponding to the side surface are disposed to match the shape of the upper frame piece 21d, and the upper frame piece 21d is placed together with the film piece 12d. Conform to frame pieces 23d and 24d. Of course, these mold pieces 21d, 23d and 24d are heated to a temperature below the melting point of the biodegradable plastic which is the main component of the coating film 12.

Then, heating and press molding using the above-described external heating or internal heating are performed. During the heating and press molding, the overlapping portion 12e is welded in the film piece 12d as described above to form a layer of the covering film 12 having no space on the surface of the foamed molded product (molding base 11c). As a result, it is possible to obtain the cup-shaped container 10c (refer to FIG. 3 (a)) as the biodegradable molding shown in the present invention by the above one step.

[Preparation 6]

In the manufacturing method 5, in the manufacturing method 6, the film piece 12c is matched in the overlap part 12d, and it is made to substantially match with the external shape of a biodegradable molding before the time before shaping | molding. Like the manufacturing method 5, the manufacturing method can also be used suitably for the purpose of forming the biodegradable molded object of a more complicated shape, such as the magnitude | size 10c shown in FIG.

This manufacturing method is basically the same as the manufacturing method 5, but forms an outline frame film which is reliably matched by welding the overlapping portions 12d and 12d in advance. For this purpose, at the time of batch molding, it is an effective method in the case of using the coating film 12 in which the overlap part 12d, 12d is difficult to be welded by the said manufacturing method 5.

Specifically, the manufacturing method 6, as shown in Fig. 19, in the mold 20d shown in Figs. (8a) and (b), the outline plastic plastic previously matched with a nearly cup shape between the upper and lower mold pieces 21d, 23d, and 24d is shown. Two sheets of 12f are overlapped and a molding raw material is further supplied between these plastic 12f and 12f. In this state, the mold 20b is heated to a temperature below the melting point of the biodegradable plastic which is the main component of the outline film 12f (coating film 12). Thereafter, the upper and lower mold pieces 21d, 23d, and 24d are combined and heated and press-molded using the above-described external heating or internal heating. By this one step, a cup-shaped container 10c (see Fig. 3 (a)) can be obtained as the biodegradable molded product shown in the present invention.

[Process 7]

In the manufacturing method 7, the method of the manufacturing method 3 is further combined in the said manufacturing method 6. That is, the film piece 12c is made to correspond to the overlap part 12d, and is made to substantially match with the exterior of a biodegradable molding at the time before shaping | molding, these are piled up and processed into a substantially bag shape, and the molding raw material is divided inside. Like the manufacturing method 5 and the manufacturing method 6, this manufacturing method can also be preferably used for the purpose of forming a biodegradable molded article having a deep drawing degree or a more complicated shape, such as the cup-shaped container 10c shown in Fig. 3 (a). have.

Also in this manufacturing method, similarly to the manufacturing method 3 or the manufacturing method 4, since the coating film 12 is prepared on the bag film, a molding combination for accommodating the molding raw material is prepared. At the same time, the preparation for molding is completed by simply putting the molding combination in a mold at once. Therefore, the manufacturing process can be further simplified.

Specifically, the manufacturing method 7 will be described. As shown in FIG. 20, the coated film 12 is made into a film piece conforming to the outer shape of the cup-shaped container 10c, and the outer frame film is matched with this, and two more sheets are matched in advance to produce a bag. It is processed into 12 g of the outer packaging film of the shape. Then, a predetermined amount of the raw material for molding 14 is divided and injected into 12 g of the outer packaging film to prepare 40 g of the molding composition. This molding combination 40g may be stored in a predetermined warehouse or the like. Subsequently, in the mold 20d shown in Figs. 8A and 8B, 40 g of the nearly cup-forming composition for molding out of the warehouse are placed on the lower frame pieces 23d and 24d. This completes the molding preparation.

In this state, the mold 20d is heated to a temperature below the melting point of the biodegradable plastic which is the main component of the covering film 12 (outer bag 12g). Thereafter, the upper and lower mold pieces 21d, 23d, and 24d are combined to be heated and press-molded using the above-described external heating or internal heating. By this one step, it is possible to obtain the cup-shaped container 10c (refer FIG. 3 (a)) as the biodegradable molding shown in this invention.

In each of the above-described attachment methods, that is, the post-attachment method and the co-adhesion method, the coating film 12 does not have to correspond to the entire foamed molded article, but only a portion to preserve the foamed molded article. For example, when the food is finished after placing it temporarily on the surface of the food, such as takoyaki, fried udon, grilled Japanese food, hot dog, fried potatoes, etc. Disposable dishes such as discarded dishes, dishes such as those generally used for supporting packaging such as cats, and the like need only be protected from the surface (the upper surface of the plate), so that the coating film 12 only needs to be attached to the surface.

For example, in the simultaneous adhesion method of the above-mentioned manufacturing methods 1-7, at the time of steam-foaming molding in a shaping | molding die, the raw material for shaping | molding is sandwiched between two coating films 12, and the whole surface of a foamed molding is made into the coating film 12. Covered. However, in the simultaneous adhesion method of the manufacturing methods 1-7, only the upper surface of foam molding may be coat | covered with the coating film 12.

In addition, in the case of using the biodegradable molded article shown in the present invention as a cushioning material used for packaging such as a telephone machine, it is only necessary to attach the coating film only to the telephone product and the back. In particular, when the telephone product is large, the back and the size must be large, and therefore, the attachment frame for attaching the coated film is also enlarged. Therefore, when the biodegradable molding is enlarged, the coated film may be attached to the minimum portion necessary.

On the other hand, for example, such as a container on the cup surface (such as a ball-shaped container 10a as shown in Figs. 1 (a) and (b)), not only the boiled water is put inside, but also the dry surface inside does not oxidize or absorb moisture. When gas impermeability is required on the entire surface of the container, it is preferable to attach the coating film 12 to the entire container.

Next, the film of the co-adhesion method which coat | covers only a part of surface of foam molding with the coating film 12 is demonstrated below.

[Manufacturer 1A]

The manufacturing method 1A is a variation of the manufacturing method 1, and instead of sandwiching molding materials between two coating films 12 in manufacturing method 1, only one sheet of coating film 12 is disposed on the top surface of the molding material, and only the top film of the coating molding is coated. There is a way to attach 12.

Specifically, this production method 1A, as shown in Fig. 22, in the mold 20b shown in Figs. 6 (a) and 6 (b), only one sheet of the covering film 12 is disposed as it is in the sheet shape between the upper and lower pieces 21b and 22b. The present invention provides a raw material 14 for forming a slurry or dough between the coating film 12 and the lower piece 22b. In this state, the mold 20b is heated to a temperature below the melting point of the biodegradable plastic which is the main component of the coating film 12. Thereafter, the upper and lower mold pieces 21b and 22b are combined and heated and press-molded using the above-described external heating or internal heating. By this one step, it is possible to obtain a dish-shaped container 10d (see Fig. 23) as the biodegradable molded product shown in the present invention.

As shown in FIG. 23, this dish-shaped container 10d coats only the upper surface of the container main body 11b in which the food was placed with the coating film 12. As shown in FIG. This dish-shaped container 10d has excellent water resistance on the upper surface on which food is placed. To this end, as described above, the use of a dish such as a disposable dish such as discarding the food and then discarding it, or a dish such as used as a support when packaging a cake can be particularly preferably used.

In the present invention, in the attachment of the coating film 12, as described above, in the post-adhesion method, it is preferable to prepare a pair of attachment frames having a cavity almost the same shape as the molding die used for molding the foamed molded product for film attachment in advance. In addition, in the case of the simultaneous adhesion method, the attachment frame can attach the coating film 12 collectively at the time of necessary molding.

Therefore, it is possible to adhere the coating film 12 to the surface of the foamed molding in a state where it is almost adhered accurately and reliably. Even when producing a molded article having a particularly complicated shape, since the shape depends on the shape of the cavity of the molding die, for example, even in the post-attachment method, the attachment frame 30 is made to fit the foamed molding or the shape is delicately adjusted. Even if it does not, it can be easily created so that it may duplicate a mold.

In addition, in the present invention, the starch, which is a natural material, is steam-foamed as a main raw material to first produce a foamed molded article having a predetermined shape, and then the coated film 12 is attached or the coated film 12 is simultaneously attached to the foam molding. Therefore, as long as the mold can be removed, it is possible to mold the molded article of any shape. For example, it can be reliably molded even in a deeply stretched shape such as a cup, a food tray or a packaging tray with a uniform thickness, and a more complicated cushioning material.

In addition, when attaching the coating film 12 by the post-attachment method, since it is possible to use the attachment frame of substantially the same shape as the shaping | molding die used for shaping | molding as mentioned above, it is based on biodegradability and is water-resistant and moisture-resistant. It is possible to obtain moldings of a wide variety of shapes that are excellent in.

In addition, when using the coating film 12 which has the gas impermeability etc. which do not have only water resistance, since it is possible to give various functions, such as gas impermeability, to the biodegradable molding shown by this invention, when using it as a container, etc. Silver can moisture-proof the oxidation of content, absorption of moisture, etc., and can provide the molded container excellent in storage property.

In addition, if a character or a picture is printed on the surface of the coating film 12 with biodegradable ink in advance, the coating film 12 may be attached. This makes it much easier to print directly on the surface of the foamed molding and makes it possible to print very beautifully and delicately on the surface of the foamed molding.

That is, in the present invention, depending on which function is to be given to the coated film 12 in advance, when the coated film 12 is attached to the foamed molded product, the biodegradable molded product shown in the present invention can be simply and surely provided with various functions. It is possible.

In addition, in the present invention, when the biodegradable molded article is used as a hermetic container for accommodating the contents therein, the container shape is often a shape having an opening. In this, a method of sealing a sheet-like sheet is mentioned as an example of the opening part which seals the inside. At this time, as shown in Fig. 21 (a), it is preferable that at least a covering film 12 is attached to a portion corresponding to the corner 16 of the opening.

In the foamed molded product, very fine irregularities are generated on the surface of the foamed molded product 11, as shown schematically in FIGS. 21 (a) and (b), in order to steam foam natural starch as a main raw material. This unevenness is mainly caused by water vapor foam molding, but if such unevenness exists, as shown in Fig. 21B, the contact state between the lid 17 and the corner 16 on the sheet is bad, and a sufficient sealing state cannot be realized.

There is also a conventional technique for applying a water-resistant resin, but since there are minute unevennesses on the surface of the foamed molded article 11, even if a certain amount of resin is applied to the surface of the unevenness, the space of the resin coated appropriately to the unevenness of the Pupils tend to be generated, and the same coating is not formed. Therefore, it is impossible to exhibit sufficient water resistance and moisture resistance. In addition, when it is necessary to prevent oxidation of the contents and the like, gas impermeability is also required, but the presence of the fine unevenness also reduces gas impermeability.

On the other hand, in the present invention, since the film 12 originally formed as a complete film is attached via an adhesive layer 13 as an example, or is softened at the same time as foam molding and adheres directly to the film, as shown in FIG. Similarly, in the corner 16, the adhesiveness between the sheet-shaped lid 17 and the corner 16 to which the covering film 12 is attached is improved. As a result, the sealing property, such as water resistance, moisture resistance, and gas impermeability, is improved in an opening part, and the storage property of an accommodation can be improved further.

As described above, in the case where the coating film 12 is partially attached, the coating film 12 and the adhesive film of any size are used at a distance between the attachment frame and the foamed molding after using the attachment frame (such as mold 30 shown in FIG. 11). It is good to arrange | position so that 13a may be inserted and attach with the same press as the above.

As described above, the biodegradable molding shown in the present invention is made by attaching a coating film made of biodegradable starch to the surface of the foamable molding having starch as the main raw material. Thereby, it is possible to give strength and water resistance to the surface, maintaining the shape retaining property (property which maintains moderate thickness) and heat insulation of the said foamed molded object. At the same time, it is possible to improve the strength and flexibility of the foamed molding.

In addition, both the foamed molding and the film have biodegradability, and in particular, the foamed molding having the thickness of starch is very biodegradable since the main ingredient is starch, and the film is made of biodegradable plastic having a slow biodegradation rate, but the film thickness is high. Small, sufficiently biodegradable. Accordingly, the biodegradable moldings shown in the present invention can exhibit good biodegradability at the time of disposal.

Furthermore, since the coating film is adhered to the surface of the foamed product with a complete film, for example, when using a container having an opening, it is possible to heatsheet a sheet-like lid at the corner of the opening or to completely close the opening. Do.

The biodegradable moldings shown in the present invention may be, for example, packaging moldings such as packaging buffers, GES, packaging plates, cup noodles, cups of utensils such as cup utensils, fried cups, disposable dishes used for food service or It can use suitably as a food container, such as a tray or containers, such as soup and juice.

In particular, since the film can be used as a container for food having a lot of water, it has gas impermeability, etc., and can be suitably used as a container for instant foods such that cup noodles can be preserved for a certain time.

Next, although this invention is demonstrated further in detail based on an Example or a comparative example, this invention is not limited to these.

In addition, the water resistance, the moisture resistance, and the state of the foamable moldability and the state of the coated film after molding in the biodegradable molded article shown in the present invention were evaluated in accordance with the above method.

[Water resistance]

The film filled with 25 degreeC water or 100 degreeC boiling water (boiling water) in a container was poured, and it left to stand at room temperature for 24 hours, and the presence or absence of deformation of the subsequent container was evaluated. ◎ It is not completely deformed by the injection of both water and film, but it is not completely deformed by adding water, but it is deformed when boiling water is added. One case was evaluated as △.

[Moisture resistance]

The container was left to stand for 24 hours in 40 degreeC, the constant temperature of 80RH%, and a humidity container, and the presence or absence of deformation | transformation of the container after that was evaluated. (Circle) the thing which was not fully deformed, and what deform | transformed the film to the grade were evaluated by x. In addition, the moisture resistance evaluation also serves as gas impermeability evaluation of a coating film.

[Foaming moldability]

In the case of producing a biodegradable molding in the co-adhesion method, the film was observed with attention to the state of foam molding of the container body in the obtained biodegradable molding. ○, the water vapor foam molding is sufficiently formed into a desired shape corresponding to the mold, and the water vapor foam molding is carried out to some extent, but a part of the shape is not formed into the desired shape corresponding to the mold, and The state which foam molding was not enough evaluated by x.

[State of coating film after molding]

In the case of producing a biodegradable molding by the co-adhesion method, the state of the coating film and the state of the mold were observed in the biodegradable molding immediately after molding. ○ A state in which the coating film does not adhere to the mold and is sufficiently coated on the surface of the biodegradable molding, and the coating film does not adhere to the mold, but a space or film is formed that is not coated on a part of the surface of the biodegradable molding. (Triangle | delta), and the state in which the coating film adhered to the metal mold | die or the coating film did not adhere to the metal mold | die and the coating film was not fully coat | covered on the surface of a biodegradable molded object were evaluated as x.

[Preparation of molding raw materials]

First, various starches (including derivatives), various additives, and water, which are the main raw materials, are uniformly mixed in a mixer so as to have the composition shown in Table 1, and the raw materials for forming the slurry (1) to (3) and (7) and dough The raw materials for molding the phases (4) to (6) and (8) were manufactured.

In addition, in order to make the characteristics of the molding raw material more clear, the amount of starch, the amount of extender, the total amount of solids, the total amount of functional additives, the total amount of raw material components, the amount of water, and the amount of functional additives added to the total amount of solids, and raw materials Table 2 shows the total amount of water added to the total amount of the ingredients separately.                 

[Formation of foam molding]

After the mold 20a shown in FIGS. 5 (a) and (b) or the mold 20b shown in FIGS. 6 (a) and (b) was heated to a temperature of 200 ° C., the cavity 25 of each mold 20a or 20b was used. The above-mentioned molding raw materials (1) to (6) are charged, and the container main body 11a (foamed product) of the ball-shaped A shown in Fig. 7 (a) and the container main body 11b (the dish-shaped B shown in Fig. 7 (b)) A total of 12 types of foamed molded articles were obtained, each of six types of foamed molded articles). The relationship between the shape of each foamed molding and the raw material for molding is shown in Table 3, and in the above description, No in Table 3 indicates the type of foamed molding.

[Coating film]

As shown in Table 4, six types of films F1 to F6 were prepared as coating films. In addition, in the following description similar to the said foamed molded object, the kind of coating film is shown as No of Table 4.

[glue]

As shown in Table 5, two types of adhesives were prepared as adhesives for attaching the coating film to the foamed molded article. In addition, the PBS film of G2 used the thickness of the range as shown in Table 5. In addition, similarly to the said foamed molded article, in the following description, the kind of adhesive agent is shown as No of Table 5.

Using the foamed molded product, the coated film, and the adhesive, the biodegradable molded product shown in the present invention was prepared by post-attachment. Below, Examples 1-21 by the post-attachment method are shown. In addition, as a comparative example for these examples, a comparative biodegradable molded article coated with a resin or wax for the foamed molded article was prepared. Below, it shows in Comparative Examples 1-3.

Example 1

For the ball-shaped A foamed molded product A1 molded from the molding raw material 1, the film F1 of the PBS resin in the coated film shown in Table 4 and the starch paste in the adhesive shown in Table 5 were selected and described in the above embodiment. As described above, coating film F1 to foam molding A11 was attached to obtain the biodegradable molding shown in the present invention. About this biodegradable molding, water resistance and moisture resistance were evaluated as mentioned above. The results are shown in Table 6.

[Examples 2 to 21]

The foamed molded article, the coated film, and the adhesive were the same as those of Example 1 except for the combination as shown in Table 6, and the biodegradable molded article shown in the present invention was obtained. Each of these biodegradable molded articles was evaluated for water resistance and moisture resistance in the same manner as in Example 1. The results are shown in Table 6.

Comparative Example 1

As shown in Table 6, foamed molded product A2 molded from the raw material for molding 2 was used, in which the shellac resin was formed using a conventional method (see Japanese Patent Application Laid-Open No. 2000-142783). That is, the comparative biodegradable molding was obtained by spray-dispersing the thing which melt | dissolved or disperse | distributed the shellac resin in alcohol in use, and then drying and forming a resin film. About this comparative biodegradable molding, water resistance and moisture resistance were evaluated similarly to Example 1. The results are shown in Table 6.

[Comparative Examples 2 and 3]

As shown in Table 6, using the foamed molded article A2 molded in the molding raw material 2 or the foamed molded article B1 molded in the molding raw material 1, the paraffin wax or microcrystalline wax for them was subjected to a temperature higher than the melting point. The comparative biodegradable molded article was obtained by forming the wax film cooled by heat-melting, spray-spraying, and cooling. About each of these comparative biodegradable moldings, water resistance and moisture resistance were evaluated similarly to Example 1. The results are shown in Table 6.

As is clear from the above results, the biodegradable moldings shown in the present invention obtained by the post-attachment method exhibit very good water resistance and moisture resistance, whereas the comparative biodegradable moldings coated on the surface by conventional means have a water resistance and None of the moisture resistance was significantly inferior. In particular, in the case of using adhesive films such as Examples 3 and 4 and Examples 6 to 21, it was found that biodegradable molded articles can be produced in a simple step, and exhibit excellent productivity.

Furthermore, in the present invention, the water content is predetermined so that the foamed moldings A1 to A6 and B1 to B6 constituting the container body of the biodegradable molding are formed by steam foam molding of the raw material for slurry or dough formation by adjusting the water content. It was excellent in having taken in the range and overcome | hardened hardness and brittleness. Therefore, it is known that the biodegradable molded article shown in the present invention, which is constituted simply by coating a film on such foamed molded articles A1 to A6 and B1 to B6, can exhibit very good strength and flexibility. In addition, the thickness after adhesion | coating of a coating film consisted of almost 30 micrometers or less.

In addition, since the weight of biodegradable plastics, such as a coating film and an adhesive layer, is suppressed to 40 weight% or less of the total weight, in the biodegradable molding shown by this invention, it also turned out that biodegradability is also very favorable compared with the conventional thing.

Next, the biodegradable molded article shown in the present invention was produced by the co-adhesion method using the molding raw material and the coating film. In the following, Examples 22 to 51 by the simultaneous deposition method are shown.

Example 22

The slurry-forming molding material (3) in the molding raw material shown in Table 1 and the modified polyester (No. F5) in the coated film shown in Table 4 were selected, and the biodegradable molded product shown in the present invention was obtained in Production Method 1. . At this time, the mold 20b shown in Figs. 6 (a) and 6 (b) was used as the molding mold, and the heating means used external heating by electrothermal heater and internal heating by high frequency heating (frequency 13.56 MHz), respectively.

In this embodiment, the heating temperature is adjusted to each of the external heating and the internal heating as the mold temperature is made of seven types of 130 ° C, 140 ° C, 150 ° C, 160 ° C, 170 ° C, 180 ° C and 190 ° C, respectively. 14 dish-type biodegradable moldings were obtained in total. In each of these biodegradable molded articles, foaming, molding, and the state of the coated film after molding were evaluated. The results are shown in Table 7.

In addition, about Examples 22-51 mentioned above including this Example, water resistance evaluation was performed only when neither the state of the foamed molded object and the coating film after molding was favorable ((circle in an evaluation)). Therefore, when either of the foaming moldability and the state of the coated film after molding is not ○, the water resistance is not evaluated. Therefore, in Tables 7 to 14, when the water resistance evaluation is not performed, "-" It is written as.

Example 23

In Example 23, 14 ball-type biodegradable moldings were obtained in the same manner as in the mold except for using the mold 20a and the manufacturing method 2 shown in FIGS. 5 (a) and 5 (b). In each of these biodegradable moldings, the foamed molded article, the state of the coated film after molding, and the water resistance were evaluated. The results are shown in Table 7.                 

Example 24

In Example 22, 14 dish-like biodegradable moldings were obtained in the same manner except that Production Method 3 was used. In these biodegradable moldings, foaming moldability, the state of the coated film after molding, and water resistance were evaluated. The results are shown in Table 7.

Example 25

In Example 23, 14 ball-type biodegradable moldings were obtained in the same manner as in the case of using Production Method 4. In these biodegradable moldings, foaming moldability, the state of the coated film after molding, and water resistance were evaluated. The results are shown in Table 7.

Example 26

In Example 22, the same as in the above-described coating method, except that the divided film piece 12d shown in Fig. 17 (a) was used as the coating film, and the manufacturing method 5 was used as the mold 20d shown in Figs. 8 (a) and (b). Fourteen cup-shaped biodegradable moldings were obtained. In these biodegradable moldings, the foaming moldability, the film state of the coating after molding, and the water resistance were evaluated. The results are shown in Table 8.

Example 27

In Example 26, 14 cup-like biodegradable moldings were obtained in the same manner as in the coating film except that the three-part film piece 12d shown in Fig. 17B was used. In these biodegradable moldings, the foaming moldability, the film state of the coating after molding, and the water resistance were evaluated. The results are shown in Table 8.

[Examples 28 to 33]

In Examples 22 to 27, PLA① (No. F3) in the coated film shown in Table 4 was selected, and the heating temperature was 100 ° C., 110 ° C., 120 ° C. in both the external heating and internal heating. Fourteen dish-shaped, ball-shaped, or cup-shaped biodegradable moldings in each of the respective examples were obtained in the same manner, except that they were adjusted individually, such as seven kinds of 130 占 폚, 140 占 폚, 150 占 폚, and 160 占 폚. In each of these biodegradable moldings, foaming moldability, the state of the coated film after molding, and water resistance were evaluated. The results are shown in Table 9 and Table 10.

[Examples 34 to 39]

In Examples 28 to 33, 14 dish-type, ball-type or cup-type biodegradable moldings of the respective examples were obtained in the same manner except that PLA2 (No. F4) in the coated film shown in Table 4 was selected. In each of these biodegradable moldings, foaming moldability, the state of the coated film after molding, and water resistance were evaluated. The results are shown in Table 11 and Table 12.

[Examples 40 to 45]

In Examples 22 to 27, PCL (No. F2) in the coated film shown in Table 4 was selected, and the heating temperature was set to 60 ° C, 70 ° C, 80 ° C for both the external heating and the internal heating. 12 dish-type, ball-type, or cup-type biodegradable moldings in each of the respective examples were obtained in the same manner, except that each was adjusted to six kinds of 90 占 폚, 100 占 폚, and 110 占 폚. In each of these biodegradable moldings, foaming moldability, the state of the coated film after molding, and water resistance were evaluated. The results are shown in Table 13 and Table 14.

Examples 46 to 51

In Examples 40 to 45, 12 dish-type, ball-type, or cup-type biodegradable moldings of each of the respective examples were obtained in the same manner except that the mat ratio (No. F6) in the coated film shown in Table 4 was selected. In each of these biodegradable moldings, foaming moldability, the state of the coated film after molding, and water resistance were evaluated. The results are shown in Table 15 and Table 16.

As will be apparent from the above results, when using the co-adhesion method, when the external heating method is selected as the heating method, it is difficult to set a more suitable mold temperature due to the characteristics of the biodegradable plastics mainly containing the coated film. It has been known that when internal heating is selected as the heating means, it is found that even a wide range of molds can be sufficiently foamed to attach a good coating film.

That is, from the results of Examples 22 to 27 shown in Tables 7 and 8, it was found that the mold temperature exceeding 150 ° C. was impossible in the external heating, whereas the molding independent of the mold temperature was possible in the internal heating. . In addition, in the results of Examples 28 to 51 shown in Tables 9 to 16, when using coating films F3 and F4 (melting points 130 DEG C and 140 DEG C) having a low melting point, good biodegradable moldings can be obtained only in the case of internal heating. okay. This makes it possible to lower the mold temperature below the melting point of the coating film and to perform molding-simultaneous-adhering, even when a particularly low temperature coating film such as 140 ° C. or lower is used.

In addition, in the biodegradable moldings (molded at mold temperatures of 150 DEG C and 160 DEG C) of Examples 22 to 27, all of which are preferably foam moldability, coatability (state of coated film) and water resistance, are produced by internal heating. Biodegradable moldings (hereinafter referred to as internal heating samples) and samples made by external heating (hereinafter referred to as external heating samples) were compared. First, the stress required to peel off the covering film was measured. As a result, the required stress was larger in the method of the internally heated sample than in the externally heated sample. In addition, the cross section of each sample was magnified and observed at a magnification of 200 times to 700 times using a stereo microscope (optical microscope), and the adhesion state of the interface between the coated film and the foamed molded article was examined. As a result, it was confirmed that the inner heating sample method had a higher adhesion between the coated film and the foamed molded product than the outer heating sample.

In these, it turned out that the internal heating sample method is better than the external heating sample regarding the adhesion state of a coating film. The reason for this is that in the case of internal heating, since the raw material for forming is generated in a short time at the beginning of foam molding and the whole expands constantly, the pressure for adhering the coating film to the mold is strongly and uniformly generated. Was considered. In fact, in the internal heating, the molding time is not extended so as to lower the initial high frequency application output, the internal pressure in the mold is also reduced, and the adhesion state of the coating film is also close to the external heating sample.

In addition, it was found that the biodegradable molding shown in the present invention obtained using the co-adhesion method exhibited very good water resistance.

[Examples 52-56]

In Example 22, a slurry-like molding material 7 or a dough-like molding is used in place of the molding raw material 3 instead of the molding raw material 3 (not shown), which is used as a molding die in place of the mold 20b. Except having used the raw material (8), it carried out similarly to Example 22, and obtained the biodegradable molded object of the shape of five round plates of 170 mm in diameter. Next, the coating film 12 at the periphery of the obtained biodegradable molding was cut about 5 mm larger than the foamed molding, and the coating films 12 of the remaining portions were welded to completely coat the foaming molding.

In addition, the coating film No. shown in Table 4. As F5 (filtrating film derived from modified polyester), one having a thickness of 50 µm was used. Moreover, the internal heating by high frequency heating (frequency 13.56 MHz) was used as a heating means, and heating temperature was adjusted so that the temperature of a metal mold might be 150 degreeC.

In Examples 53, 54 and 56, the height of the cavity of the mold (molding die) used for molding-simultaneous-adhering was changed in Example 52 to change the thickness of the biodegradable molding. On the other hand, in Examples 53 to 56, the internal pressure in the cavity of the mold (molding die) was changed in Example 52 at the time of molding-simultaneous-attachment to change the foaming ratio (air volume fraction) of the biodegradable molding. These molding conditions are shown in Table 17 together with the types of raw materials for molding.

In each of the obtained biodegradable moldings, the biodegradable foam to the weight (A) of the coated film portion, the weight (B) of the molded foam portion, their total weight (gross weight) (C), and the total volume of the biodegradable moldings The ratio (volume ratio of air phase) of the air phase contained in the molding was measured. The measurement results are shown in Table 18. In the table, "%" represents volume%.

[Comparative Example 4]

The 50-micrometer-thick thing of the coating film No. F5 (coating film derived from modified polyester) shown in Table 4 was cut out to the round shape of diameter 170mm, and the film was obtained as a molded object for a comparative control.

Next, the biodegradation test was done in the biodegradable moldings of Examples 52-56 and the film of Comparative Example 4 as follows. First, each sample was embedded in the pig manure deposit in the composting process, a part of every sample was recovered for 3 weeks, and the weight of the sample was measured. Therefore, the weight reduction rate (reduction rate) of each sample was calculated | required and it was set as the biodegradation index.

Further, the weight loss rate is determined as follows by the initial weight of the sample and the weight of recovery time (after biodegradation).

(Reduction of weight) = (initial weight)-(weight at the time of collection)

(Weight loss rate) = (weight loss) ÷ (initial weight)

The changes in the weight loss ratios of the biodegradable moldings of Examples 52 to 56 thus obtained and the films of Comparative Example 4 are shown in Table 19.

As described above, in Examples 52 to 56, as a coating film, after 18 hours of slowing in all cases, regardless of the use of the coating film of No. F5, which is the most difficult to biodegrade in the coating film shown in Table 4, The biodegradable moldings were completely degraded. On the other hand, in the molded article of Comparative Example 4 composed of only the coated film, 15% by weight did not decompose even after 18 weeks. From these comparisons, it was found that the biodegradable molded article according to the present invention has higher biodegradability than the coating film itself due to the presence of the foamed molded article.

only. The biodegradable molding of Example 56 remained undissolved at 5 wt% after 15 weeks, and the decomposition rate was slightly slower than the biodegradable moldings of Examples 52 to 55. It is considered that the ratio of the weight of the foamed molding to the total weight of the biodegradable molding is lower than 47.8% by weight, and at the same time, the air volume fraction (foaming rate) is lower than 5% by weight.

On the other hand, the biodegradable moldings of Examples 54 and 55 having a ratio of the weight of the foamed molding to the total weight of the biodegradable moldings of 63.9% or more by weight and Examples 52 and 53 having an air volume fraction of 33% or more were used after 15 weeks. It fully decomposed and was excellent in biodegradability.

Therefore, the biodegradable moldings according to the present invention are very, if the proportion of the weight of the foamed moldings in the total weight exceeds 50% by weight (particularly 60% by weight or more), or the air phase volume ratio exceeds 30%. It was found to exhibit good biodegradability.

[Examples 57-60]

First, four types of coating films F3 ', F4', F5 ', and F7' shown in Table 20 were prepared as coating films.

And as a raw material for shaping | molding, the dough-like shaping | molding raw material 8 shown in Table 1, and the coating film of the four types of coating films F3 ', F4', F5 ', F7 shown in Table 20, and a shaping | molding die are shown in FIG. By the manufacturing method 3 which used the metal mold | die 20a shown by and (b), respectively, four ball-shaped biodegradable molded objects were obtained in total. In addition, as a heating means, internal heating by high frequency heating (frequency 13.56 MHz) was used, and mold temperature was 120 degreeC in case of coating films F3 'and F4', 150 degreeC in case of coating film F5 ', and coating film F7'. In the case of, the heating temperature was adjusted to be 170 ° C.

As each biodegradable molded article, a boiling continuation test and a microwave heating test were conducted, and the state of the coating film and the state (with or without deformation) of the biodegradable molded article were examined.

The boiling continuation test was performed as follows. That is, 400 cm3 of boiling water is put inside each biodegradable molding, and the heating and heating heater in the boiling water is put in a boiling state to maintain boiling state for 10 minutes, so that the state of the coated film and the form of the biodegradable molding are maintained. Investigated.

The electron lens heating test was performed as follows. That is, 400 cm <3> of water was put inside each biodegradable molding, and the biodegradable molding containing the water was heated for 10 minutes at an output 600W using a microwave oven for home, and the state of the coating film and the shape of the biodegradable molding were Investigated.

Table 21 shows the results of the continuous boiling test and the microwave heating test.

As shown in Table 21, biodegradable moldings (Examples 59 and 60) using resin films F5 'and F7' having a softening start temperature of 130 ° C or higher and a melting point of 170 ° C or higher were subjected to boiling continuous test and microwave heating. In neither of the tests, the softening of the film and the deformation of the molding itself were not seen. Therefore, it was found that the biodegradable molded article using the coating film whose softening start temperature was 130 degreeC or more and melting | fusing point 170 degreeC or more was very excellent in hot water resistance (resistance to high temperature hot water).

Example 61

Dough-shaped molding raw material 8 shown in Table 1 as the raw material for molding, three types of coated films F4 ', F5', F7 'described in Table 20 as the coated film, and FIGS. 6 (a) and (b) as a mold. The die 20b shown in the above was used, respectively, and manufacturing method 1A obtained three dish-shaped biodegradable moldings in total. When using the coating film F4 ', only the internal heating by high frequency heating (frequency 13.56 MHz) was used for the heating method, and heating temperature was adjusted so that heating temperature might fall and become 120 degreeC. In the case of coating film F5 ', the heating temperature is adjusted so that the mold temperature is heated to 150 ° C by using both directions of internal heating by high frequency heating (frequency 13.56 MHz) and external heating by electric heater. did. In the case of coating film F7 ', the heating temperature was adjusted so that mold temperature might be 170 degreeC, using both directions of the internal heating by high frequency heating (frequency 13.56MHz) and the external heating by an electric heater.

The obtained biodegradable molded article is coated with only a coating film on the upper surface with respect to the surface on which the food is placed, as in the dish-shaped container 10c shown in FIG.

In the biodegradable moldings obtained by these five kinds of manufacturing methods, water resistance was evaluated. As a result, any biodegradable molded article was not completely deformed even after injecting water at 25 ° C. for 24 hours. Therefore, as with the dish-shaped container 10d shown in FIG. 23, it was found that even a biodegradable molded article coated with only a part of the foam molded article surface has sufficient water resistance in simple applications.

In addition, specific aspect or embodiment in terms of an optimal form for implementing this invention is only to clearly the technical content of this invention, It is limited only to a specific example as such, It is not interpreted only by consultation, Various modifications may be made within the spirit of the invention and the scope of the claims set forth below.

As described above, the biodegradable molded article of the present invention comprises a biodegradable foamed molded article and a coated film adhered to the surface thereof, wherein the coated film is composed of biodegradable plastics as a main component, and has a biodegradable molded article having at least hydrophobicity. The above-mentioned biodegradable foamed molded article has a structure in which all or derivatives thereof are molded by steam foaming the raw material for molding a slurry or dough obtained by mixing water therein.

Therefore, in the above configuration, the raw material is made of steam using the raw material for forming a slurry or dough with starch as the main component. Therefore, it has the effect that it can be easily molded into a very complicated shape and at the same time possesses a moisture content of the degree that the foamed molded product obtained is molded, and can exhibit superior strength as compared with conventional starch molded products.

Besides. In order to adhere the coated film having biodegradability to the foamed molded product, it is possible to coat the coated film reliably and easily with the foamed molded product having sufficient strength, and to provide various functions such as water resistance and gas impermeability. It also has the effect that it can be added.

The biodegradable molded article of the present invention is preferably a biodegradable molded article having the above constitution, wherein the weight of the biodegradable foamed article in the total weight is 60% by weight or more.

Accordingly, in the above configuration, since the biodegradable plastic having a low biodegradation rate is configured to be suppressed to at least 40% by weight of the total, the biodegradation of the biodegradable plastic and the biodegradable foamed molding is good, and accordingly, In addition, there is an effect that the biodegradability of the biodegradable molding can be further improved.

In the biodegradable molding of the present invention, preferably, in the biodegradable molding of the above constitution, in the biodegradable molding of the constitution, the ratio of the volume of the air phase contained in the biodegradable foamed molding to the total volume is It is composed of more than 30% by volume.

According to the said structure, the surface area of a biodegradable foamed molding becomes large, and microorganisms which biodegrade a biodegradable foamed molding are easy to pick up. Therefore, the biodegradable foam molding is easily biodegradable. As a result, the above structure results in that the biodegradability of the biodegradable molding can be further improved.

The biodegradable molding of the present invention preferably contains, in the biodegradable molding of the above constitution, water in the range of 20% by weight to 70% by weight when the whole raw material for molding is 100% by weight. It is a constitution.

Therefore, in the above configuration, in order to include a suitable amount of water in the raw material for molding, the obtained foamed molded article has a desirable water content for exhibiting sufficient strength. As a result, it was possible to produce biodegradable moldings collectively by adhering the coated film in a continuous process after steam foam molding or by simultaneously adhering at the time of foam molding to improve and control the moisture content. .

The biodegradable molded article of the present invention is preferably a biodegradable molded article having the above-described configuration, in which the coating film is directly attached to the surface of the biodegradable foamed molded article in almost close contact.

Therefore, in the above structure, since the coating film is directly attached in a state of almost adhered to the surface of the foamed molded product, the coated film does not easily peel off from the surface of the foamed molded product. For this purpose, it is possible to more reliably adhere the coating film to the foamed molding, and at the same time, it is possible to secure the biodegradability of the obtained biodegradable molding.

In the biodegradable molding of the present invention, in the biodegradable molding of the above constitution, the coating film may be attached to the surface of the biodegradable foamed molding with an adhesive having biodegradability.

Therefore, according to the above constitution, the biodegradable adhesive can be used to more securely attach the coating film to the foamed molding, and the biodegradability of the obtained biodegradable molding can be ensured.

In the biodegradable molded article of the present invention, preferably, in the biodegradable molded article of the above constitution, the biodegradable foamed molded article has a final water content in the range of 3% by weight to 20% by weight.

Therefore, in the above configuration, since the foamed molded article contains an appropriate amount of water, the foamed molded article exhibits sufficient strength. For this purpose, it has the effect which can further improve the strength and durability of the obtained biodegradable molding.

In the biodegradable molded article of the present invention, preferably, the coating film has a softening start temperature of 130 ° C or higher and a melting point of 170 ° C or higher.

Therefore, in the above configuration, softening or melting of the coating film is unlikely to occur. Thereby, there exists an effect which can reliably avoid the deformation | transformation of a biodegradable molded object by heat.

As described above, the method for producing a biodegradable molded article of the present invention is a biodegradable foamed molded article having a predetermined shape by steam foaming a raw material for forming a slurry or dough obtained by using starch or a derivative thereof as a main component and mixing water therewith. And a step of molding the coated film having at least hydrophobicity as a main component of the biodegradable plastic, followed by heating and softening the film to be pressed to adhere to the surface of the biodegradable foamed molding.

Therefore, in the above method, first, after forming a slurry- or dough-like molded product containing starch as a main component, the biodegradable coating film is heated and pressed. To this end, it is possible to obtain a moisture content of a degree capable of exhibiting sufficient strength at the time of molding, and to stably attach the coating film to the main body (foamed product) having a stable moisture content. Therefore, the effect that it is possible to manufacture the biodegradable molding which is much superior to the conventional one by the simple method was acquired.

In the method for producing a biodegradable molded article of the present invention, in the production method, a predetermined molding die is used in the molding step, and an attachment mold having a shape substantially the same as the molding die is used in the attaching step. How is it good?

Therefore, in the above method, it is easier to create an attachment frame by copying the attachment frame conforming to the mold than in the past, so as to use an almost identical shape as the attachment frame for the foamed molding and the coating film of the foamed molding. It has the effect of being possible. In addition, since the coating film having almost the same mold is attached, it also has the effect that it is possible to produce a biodegradable molding in a simpler process.

The method for producing a biodegradable molded article of the present invention is a method for producing a biodegradable molded article according to the above method, wherein, in the attaching step, before the coating film is attached, between the coating film and the biodegradable foamed molding, the meltable temperature is lower than the melting point of the coating film. A method of disposing an adhesive film made of a biodegradable plastic having a melting point may also be used.

Therefore, in the above method, it is possible to reliably adhere the coated film to the surface of the foamed molded product so that the adhesive film is softly pressed and the adhesive is melted by simply sandwiching the adhesive previously formed into a film between the coated film foamed moldings. . As a result, it has the effect that it is possible to further simplify the manufacturing method of a biodegradable molding.

The manufacturing method of the biodegradable molding of this invention may be the method in which the said coating film is previously shape | molded in the shape nearly coincident with the external shape of the obtained biodegradable molding in the said manufacturing method.

Therefore, in the above method, since the coating film is first molded into a shape almost coincident with the outline of the biodegradable molding, the coating film is not torn, and the biodegradable molding having a deep drawing is well formed. As a result, it has the effect that it is possible to reliably and effectively coat the coating film with respect to foamed molding.

Another method for producing a biodegradable molding of the present invention, as described above, by heating the molding raw material and the coating film in a molding frame, while steam-forming the biodegradable foam molding of a predetermined shape, and heating the coating film, Softening and squeezing are methods including finally forming-simultaneous-adhering process by attaching the coating film to the surface of the biodegradable foamed molding.

Therefore, in the above-described method, after the foaming molding of the molding raw material and the adhesion of the coating film are carried out simultaneously in one step, in the obtained biodegradable molding, the coating film is directly adhered in a state of being in close contact with the surface of the foamed molding. It is possible. Therefore, it is possible to manufacture a biodegradable molded article which is very superior to the conventional one by a simpler method, and at the same time, it is possible to further stabilize the adhesion state of the coated film in the obtained biodegradable molded article.

According to another method for producing a biodegradable molding of the present invention, when the raw material for molding is inserted into a coating film and then heated in a molding mold, it is possible to obtain a biodegradable molding in which the entire surface of the biodegradable foam molding is coated with the coating film. It also has the effect.

Another method for producing a biodegradable molded article of the present invention is preferably a method for directly heating the molding raw material by dielectric heating such as high frequency dielectric heating in the forming-simultaneous-attaching step in the manufacturing method. .

According to the said method, in the initial stage at the time of coating shaping | molding, the shaping | molding raw material heats in a short time, and the whole expands uniformly. More than this, the coating film is pressed against the molding die, so that the pressure is strong and uniformly generated. As a result, the method has the effect that it is possible to obtain a biodegradable molded article having high adhesion between the biodegradable foamed molded article and the coated film.

In addition, according to the above method, since the raw material for molding is directly heated without heating the molding raw material through the mold, even if the temperature of the molding die is set to a relatively low temperature, the raw material for molding is sufficiently heated. It becomes possible to adhere to the coating film. Therefore, the above method can have a coating film having a low melting point, and also has an effect that the degree of freedom of selection of the coating film is high.

The manufacturing method of the biodegradable molding of this invention may be the method in which the said coating film is previously shape | molded in the shape nearly coincident with the external shape of the obtained biodegradable molding in the said manufacturing method.

Therefore, in the above method, since the coating film is first molded into a shape almost coincident with the outline of the biodegradable molding, the coating film is not torn, and the biodegradable molding having a deep drawing is molded well. As a result, it has the effect that it is possible to reliably and effectively coat the coating film with respect to foamed molding.

The manufacturing method of the biodegradable molding of this invention may be a method in which the said coating film consists of a film piece cut | disconnected in the shape substantially corresponded to the external shape of the obtained biodegradable molding in the said manufacturing method.

In the above method, therefore, the shape of the coating film before adhesion is set in a shape that conforms to the shape after molding in advance, so that the biodegradable molded article having a coated film or a deeply stretched shape can be satisfactorily formed. As a result, it has the effect that it is possible to reliably and effectively coat the coating film with respect to foamed molding.

The manufacturing method of the biodegradable molding of this invention may be the method of the said manufacturing method WHEREIN: The said coating film is processed into the bag shape so that the raw material for shaping | molding can be accommodated further inside.

Therefore, in the above method, the coating film is processed into a bag shape so that it can be preserved for a predetermined time in order to put the molding material therein and become almost packed, and then at the time of producing a biodegradable molding, The batch preparation is prepared by putting into a molding die collectively. Therefore, it has the effect that it is possible to further simplify a manufacturing process.

The composition for foam molding according to the present invention contains a starch or a derivative thereof as a main component in a bag film processed into a substantially bag shape as described above, and contains a slurry or dough-like raw material obtained by mixing water therein. In addition, the bag is composed of a coated film having a biodegradable plastic as a main component and having at least hydrophobicity.

Therefore, in the above configuration, it is possible to inject a large amount of the raw material for molding into the bag-shaped covering film in advance, and to preserve it for a predetermined time. In addition, it is possible to easily prepare a biodegradable molding having a coating film containing biodegradable plastic as a main component on the surface thereof by putting it in a mold and steam foam molding. To this end, it is possible to produce biodegradable moldings in an easy and simple process.

Claims (22)

A biodegradable molded article formed into a predetermined shape, and a coated film adhered to the surface thereof, wherein the coated film has a melting point of 170 ° C. or higher and is composed of biodegradable plastics as a main component and has at least hydrophobicity. In The biodegradable foamed molded article has a starch or a derivative thereof as a main component, a slurry or dough-like molding material obtained by mixing water therein, a melting point of 170 ° C or higher, and a biodegradable plastic as a main component, and has at least hydrophobicity. Using the coated film, The heating of the molding raw material and the coating film is performed by internal heating to heat the molding raw material itself in the molding die, and the biodegradable foamed molding having a predetermined shape is steam-foamed, and the coating film is heated and softened and pressed. And finally producing the biodegradable molded article comprising a molding-simultaneous-adhesive step of attaching the coating film to the surface of the biodegradable foamed molding. The biodegradable molding according to claim 1, wherein the weight of the biodegradable foamed molding is 60% by weight or more in the total weight. The biodegradable molding according to claim 1 or 2, wherein the proportion of the volume of the air phase contained in the biodegradable foam molding is greater than 30% by weight relative to the total volume. The biodegradable molding according to claim 1 or 2, wherein the molding raw material contains water in a range of 20% by weight or more and 70% by weight or less when the whole raw material is 100% by weight. The biodegradable molding according to claim 1 or 2, wherein the coating film is directly attached in a state of being in close contact with the surface of the biodegradable foam molding. The biodegradable molding according to claim 1 or 2, wherein the coating film is attached with a biodegradable adhesive to the surface of the biodegradable foamed molding. The biodegradable molding according to claim 1 or 2, wherein the biodegradable foamed molding has a final water content in the range of 3% by weight to 20% by weight. The biodegradable molding according to claim 1 or 2, wherein the coating film has a softening start temperature of 130 ° C or higher. A biodegradable foamed molded article having a predetermined shape is formed by heating the raw material for molding in the form of a slurry or a dough obtained by mixing starch or a derivative thereof with water, and heating the raw material for molding itself in the mold. Forming process of steam foam molding, Biodegradation comprising melting process having a melting point of 170 ° C. or higher and comprising biodegradable plastic as a main component, and at least the hydrophobic coating film is softened by heating and pressing to adhere to the surface of the biodegradable foamed molding. Method for producing a molded article. 10. The method for producing a biodegradable molding according to claim 9, wherein a predetermined mold is used in the molding step, and an attachment mold having substantially the same shape as the mold is used in the attaching step. Biodegradable foam having a predetermined shape by heating the raw material for forming a slurry or dough formed by using starch or a derivative thereof as a main component and mixing water therein with internal heating for heating the raw material for molding itself in a predetermined mold. A molding process of steam foam molding the moldings, The biodegradable plastics are the main ingredient, and at least the hydrophobic coating film is heated and softened, and then pressed and adhered to the surface of the biodegradable foamed molding, wherein an attachment frame having an almost same shape as the predetermined mold is used. In the method for producing a biodegradable molding comprising a step of attaching, In the attaching step, a biodegradable adhesive film made of biodegradable low melting point biodegradable plastic is disposed between the coated film and the biodegradable foamed molding at a temperature lower than the melting point of the coated film before the coating film is attached. Method of Making Molded Products. The method for producing a biodegradable molded product according to claim 9 or 10, wherein the coating film is previously molded into a shape that almost matches the appearance of the obtained biodegradable molded product. Using a coating film having a melting point of 170 ° C. or higher, a biodegradable plastic as a main component, and a coating film having at least hydrophobicity, as a main component of starch or a derivative thereof, and obtained by mixing water therein with a slurry or dough shape. The heating of the molding raw material and the coating film is performed by internal heating to heat the molding raw material itself in the molding die, and the biodegradable foamed molding having a predetermined shape is steam-foamed, and the coating film is heated and softened and pressed. And finally a molding-simultaneous-adhering step of attaching the coating film to the surface of the biodegradable foamed molding. The method for producing a biodegradable molding according to claim 13, wherein the internal heating for heating the molding raw material itself in the molding mold after sandwiching the molding raw material between the covering films is dielectric heating. The method for producing a biodegradable molded product according to claim 13 or 14, wherein in the forming-simultaneous-attaching step, the raw material for molding is directly heated by dielectric heating. 15. The method for producing a biodegradable molded product according to claim 13 or 14, wherein the coating film is previously molded into a shape substantially conforming to the appearance of the obtained biodegradable molded product. The method for producing a biodegradable molded product according to claim 13 or 14, wherein the coating film is formed of a film piece cut into a shape substantially conforming to the appearance of the obtained biodegradable molded product. The method of claim 13 or 14, wherein the coating film is additionally processed into a bag shape to accommodate a molding material therein. The raw material for molding in the form of a slurry or a dough obtained by mixing starch or a derivative thereof as a main component and mixing water therein is contained in the bag film processed in a substantially bag shape. The method of producing a biodegradable molding is characterized in that the bag film uses a composition for foam molding which is composed of a coating film having a biodegradable plastic as a main component and has at least hydrophobicity. 10. The method of claim 9, wherein the internal heating for heating the molding raw material itself in the mold is dielectric heating. A biodegradable molded article formed into a predetermined shape, and a coated film adhered to the surface thereof, wherein the coated film has a melting point of 170 ° C. or higher and is composed of biodegradable plastics as a main component and has at least hydrophobicity. In The biodegradable foamed molded article is composed of starch or derivatives thereof as a main component, and heating of the raw material for molding in the form of slurry or dough obtained by mixing water therein is performed by internal heating for heating the raw material for molding in the mold. Forming a steam of the biodegradable foamed molding of Preparation of a biodegradable molding having a melting point of 170 DEG C or more, comprising biodegradable plastics as a main component, and an adhesive step of adhering the coated film having at least hydrophobicity by heating to soften it and then attach it to the surface of the biodegradable foam molding Biodegradable moldings are produced by the method. A biodegradable molded article formed into a predetermined shape, and a coated film adhered to the surface thereof, wherein the coated film has a melting point of 170 ° C. or higher and is composed of biodegradable plastics as a main component and has at least hydrophobicity. In The biodegradable foamed molding includes a raw material for forming a slurry or dough obtained by using starch or a derivative thereof as a main component, and mixing water therewith, A coating film having a melting point of 170 ° C. or higher and having a biodegradable plastic as a main component and having at least hydrophobicity is used, and the coating film is 3-hydroxybutyl acid-3-hydroxy valeric acid copolymer, poly-p-hydride. Roxybenzaldehyde (PHB), polybutylene susinate (PBS), polycaprolactone (PLC), acetylcellulose based polymer, polyethylene susinate (PESu), polyester amide, modified polyester, mother-by and cellulose chitosan complex Using a coating film made of at least one or two kinds of biodegradable plastics selected from the group consisting of The heating of the molding raw material and the coating film is performed by internal heating to heat the molding raw material itself in the molding die, and the biodegradable foamed molding having a predetermined shape is steam-foamed, and the coating film is heated and softened and pressed. And finally producing the biodegradable molded article comprising a molding-simultaneous-adhesive step of attaching the coating film to the surface of the biodegradable foamed molding.

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